1 00:00:16,480 --> 00:00:20,920 okay so um today we're want to start 2 00:00:19,199 --> 00:00:23,080 talking about the long run I've been 3 00:00:20,920 --> 00:00:24,400 talking about the business cycles and 4 00:00:23,079 --> 00:00:27,919 today we're going to start talking about 5 00:00:24,399 --> 00:00:30,559 things that happen over decades H but 6 00:00:27,920 --> 00:00:34,280 before I do that before we finish with 7 00:00:30,559 --> 00:00:36,238 the the short run medium run I just 8 00:00:34,280 --> 00:00:38,480 don't want you to I want I don't want to 9 00:00:36,238 --> 00:00:41,280 give you the impression that that you 10 00:00:38,479 --> 00:00:43,359 know once you understand the ISL MPC 11 00:00:41,280 --> 00:00:44,679 sort of you you can start managing 12 00:00:43,359 --> 00:00:47,399 monetary 13 00:00:44,679 --> 00:00:50,399 policy immediately I 14 00:00:47,399 --> 00:00:52,280 I there's a lot of noise of all sort of 15 00:00:50,399 --> 00:00:57,439 kind of complexity in the real world of 16 00:00:52,280 --> 00:01:01,439 course that can make um policies 17 00:00:57,439 --> 00:01:03,718 uh uh very hard to manage in practice 18 00:01:01,439 --> 00:01:06,319 macroeconomic policies and one 19 00:01:03,719 --> 00:01:09,599 fundamental principle I would say is 20 00:01:06,319 --> 00:01:14,079 that policy makers understand that speed 21 00:01:09,599 --> 00:01:16,839 can kill okay and uh that's very obvious 22 00:01:14,079 --> 00:01:19,959 during financial crisis there we all 23 00:01:16,840 --> 00:01:22,680 understand that ER the response needs to 24 00:01:19,959 --> 00:01:25,438 be large it has to be a response with 25 00:01:22,680 --> 00:01:27,240 overwhelming Force essentially because 26 00:01:25,438 --> 00:01:28,798 things are happening so fast that very 27 00:01:27,239 --> 00:01:31,118 few corporations even healthy 28 00:01:28,799 --> 00:01:33,600 corporations that that can adjust 29 00:01:31,118 --> 00:01:35,200 quickly enough uh to the PACE at which 30 00:01:33,599 --> 00:01:39,158 things are changing prices become 31 00:01:35,200 --> 00:01:40,680 noninformative uh fire cells take place 32 00:01:39,159 --> 00:01:42,560 and and and obviously it's very 33 00:01:40,680 --> 00:01:45,118 difficult to make economic decisions in 34 00:01:42,560 --> 00:01:47,040 that context and so that's the reason 35 00:01:45,118 --> 00:01:48,478 they are the speed in the on the on the 36 00:01:47,040 --> 00:01:51,040 policy Direction goes very clearly in 37 00:01:48,478 --> 00:01:52,879 One Direction do it quickly and very 38 00:01:51,040 --> 00:01:56,399 large 39 00:01:52,879 --> 00:01:57,879 now on the other hand ER when you're 40 00:01:56,399 --> 00:02:00,718 going through a period in which you're 41 00:01:57,879 --> 00:02:05,438 are hiking interest rates for example 42 00:02:00,718 --> 00:02:07,640 ER like we're going through now um the 43 00:02:05,438 --> 00:02:10,038 the Tendencies towards gradualism to do 44 00:02:07,640 --> 00:02:13,719 it very slowly because something can 45 00:02:10,038 --> 00:02:16,279 break along the path and it's often the 46 00:02:13,719 --> 00:02:19,479 case that with for sufficiently large 47 00:02:16,280 --> 00:02:21,759 adjustments something breaks okay and so 48 00:02:19,479 --> 00:02:24,719 here you have an example of sort of 49 00:02:21,759 --> 00:02:27,399 major episodes of hiking in the US and 50 00:02:24,719 --> 00:02:30,598 things that have happened about those 51 00:02:27,400 --> 00:02:32,959 those H major episodes 52 00:02:30,598 --> 00:02:35,719 this one actually I I have a personal 53 00:02:32,959 --> 00:02:38,039 attachment to that one because you know 54 00:02:35,719 --> 00:02:40,239 I was studying in Chile around then 55 00:02:38,039 --> 00:02:42,158 everything was going wonderfully massive 56 00:02:40,239 --> 00:02:44,599 Capital flows to Chile emerging markets 57 00:02:42,158 --> 00:02:48,359 were very popular we all felt very 58 00:02:44,598 --> 00:02:51,238 wealthy rich and so on and right after I 59 00:02:48,360 --> 00:02:53,120 finished College ER I was not planning 60 00:02:51,239 --> 00:02:56,080 to come to the usy things were going 61 00:02:53,120 --> 00:02:58,239 very well in Chile H but the US decided 62 00:02:56,080 --> 00:02:59,840 to hike interest rate very aggressively 63 00:02:58,239 --> 00:03:01,800 all of the sudden Capital flows to 64 00:02:59,840 --> 00:03:05,120 emergy markets disappear we went into an 65 00:03:01,800 --> 00:03:06,840 enormous financial crisis I lost I had 66 00:03:05,120 --> 00:03:09,439 no opportunity cost and I had to come to 67 00:03:06,840 --> 00:03:12,840 study to the US that that's my so I know 68 00:03:09,439 --> 00:03:15,120 that hikes aggressive hikes can matter 69 00:03:12,840 --> 00:03:15,840 can make differences to people but and 70 00:03:15,120 --> 00:03:18,759 that 71 00:03:15,840 --> 00:03:21,080 was there's a decade that followed that 72 00:03:18,759 --> 00:03:23,919 episode that is called the L decade of 73 00:03:21,080 --> 00:03:26,440 Latin America essentially so things did 74 00:03:23,919 --> 00:03:28,719 break and and one of the main reasons 75 00:03:26,439 --> 00:03:30,400 they did break is because at the time 76 00:03:28,719 --> 00:03:32,479 most of the capital close that's not 77 00:03:30,400 --> 00:03:36,319 what happens today we really being 78 00:03:32,479 --> 00:03:38,079 managed by global Banks and the banks 79 00:03:36,318 --> 00:03:41,560 can get very distressed when interest 80 00:03:38,080 --> 00:03:43,760 rate rise H very very quickly and so 81 00:03:41,560 --> 00:03:46,640 that that was essentially a problem with 82 00:03:43,759 --> 00:03:49,919 us the US Banks major Global Banks but 83 00:03:46,639 --> 00:03:51,759 the US Banks in particular that trigger 84 00:03:49,919 --> 00:03:54,518 an Emerging Market 85 00:03:51,759 --> 00:03:56,318 crisis this one also had huge 86 00:03:54,519 --> 00:03:58,680 consequences actually and it's 87 00:03:56,318 --> 00:04:02,759 interesting because this episode is is 88 00:03:58,680 --> 00:04:05,239 similar to to to to what we're going on 89 00:04:02,759 --> 00:04:08,840 what is going on right now or what may 90 00:04:05,239 --> 00:04:11,920 happen in soon so this is episode of 91 00:04:08,840 --> 00:04:15,319 hikes that ended what is called The 92 00:04:11,919 --> 00:04:17,319 Savings and Loan crisis and those so the 93 00:04:15,318 --> 00:04:20,079 best parallel to today are the small 94 00:04:17,319 --> 00:04:21,680 Regional Banks if you will and they they 95 00:04:20,079 --> 00:04:23,560 weren't able to withstand this sort of 96 00:04:21,680 --> 00:04:26,000 sharp rise in interest rate which is 97 00:04:23,560 --> 00:04:29,240 very much what is going on right now in 98 00:04:26,000 --> 00:04:32,439 the US this one actually end up with 99 00:04:29,240 --> 00:04:35,160 also another problem which is the the 100 00:04:32,439 --> 00:04:37,879 the bubble burst in Japan episode of 101 00:04:35,160 --> 00:04:41,280 hiking in the US and there we had a 102 00:04:37,879 --> 00:04:42,399 major crisis in in Japan the price of 103 00:04:41,279 --> 00:04:46,198 real estate 104 00:04:42,399 --> 00:04:47,758 collapsed ER and and essentially they 105 00:04:46,199 --> 00:04:51,639 since then they have never been able to 106 00:04:47,759 --> 00:04:54,080 grow as they used to before that that 107 00:04:51,639 --> 00:04:57,199 episode that's called sometimes the 108 00:04:54,079 --> 00:04:59,959 tequila crisis it's a Mexican 109 00:04:57,199 --> 00:05:02,560 Bond crisis and it was again the result 110 00:04:59,959 --> 00:05:06,000 of a hiking episode in the US conditions 111 00:05:02,560 --> 00:05:08,000 tighten to Emerging Market ER their bone 112 00:05:06,000 --> 00:05:10,759 Market essentially 113 00:05:08,000 --> 00:05:13,399 exploded um well this is the global 114 00:05:10,759 --> 00:05:16,280 financial crisis the Great Recession it 115 00:05:13,399 --> 00:05:22,318 was again preceded by episode of sort of 116 00:05:16,279 --> 00:05:24,879 aggressive hikes which eventually er um 117 00:05:22,319 --> 00:05:26,560 led to a turn around as house prices 118 00:05:24,879 --> 00:05:28,560 were Rising steadily throughout the 119 00:05:26,560 --> 00:05:31,120 episode and a lot of financial assets 120 00:05:28,560 --> 00:05:33,360 were created around that housing wealth 121 00:05:31,120 --> 00:05:35,038 that was been created that hike and 122 00:05:33,360 --> 00:05:37,080 interest rate eventually put a stop an 123 00:05:35,038 --> 00:05:39,519 end to that that appreciation of house 124 00:05:37,079 --> 00:05:42,918 prices in fact they turn around and it 125 00:05:39,519 --> 00:05:45,198 led to a very significant financial 126 00:05:42,918 --> 00:05:48,240 crisis and this is where we're at right 127 00:05:45,199 --> 00:05:52,680 now okay and so we already seen sort of 128 00:05:48,240 --> 00:05:54,800 some Tremors and so on so the point is 129 00:05:52,680 --> 00:05:56,600 when when sometimes you say well why is 130 00:05:54,800 --> 00:05:58,600 isn't the FED more aggressive if we have 131 00:05:56,600 --> 00:06:01,199 high inflation and go very quickly at it 132 00:05:58,600 --> 00:06:04,240 well it's because things can go wrong 133 00:06:01,199 --> 00:06:05,840 okay and it it typically happens that 134 00:06:04,240 --> 00:06:08,918 things do go wrong you don't know 135 00:06:05,839 --> 00:06:11,399 exactly what will blow up but something 136 00:06:08,918 --> 00:06:13,279 may blow up and typically is associated 137 00:06:11,399 --> 00:06:15,198 to some Financial Market that is very 138 00:06:13,279 --> 00:06:16,638 hot and the market and the banks are 139 00:06:15,199 --> 00:06:17,879 always involved in that because the 140 00:06:16,639 --> 00:06:20,280 banks are very 141 00:06:17,879 --> 00:06:22,360 lever you know they have little Capital 142 00:06:20,279 --> 00:06:24,239 relative to the assets they have and 143 00:06:22,360 --> 00:06:26,840 that means small variation in the price 144 00:06:24,240 --> 00:06:28,560 of assets can lead to very large H 145 00:06:26,839 --> 00:06:32,239 changes in the value of their 146 00:06:28,560 --> 00:06:35,720 capital anyway so just a warning so if 147 00:06:32,240 --> 00:06:38,759 you get a job at the FED please be 148 00:06:35,720 --> 00:06:42,000 careful okay now let me switch gears and 149 00:06:38,759 --> 00:06:43,319 and we're going to talk about um um 150 00:06:42,000 --> 00:06:45,720 something a little different from what 151 00:06:43,319 --> 00:06:48,560 we have been discussing up to now so 152 00:06:45,720 --> 00:06:51,840 this is some this is growth projections 153 00:06:48,560 --> 00:06:53,959 for different regions in the world ER 154 00:06:51,839 --> 00:06:55,519 this is something that is in publishing 155 00:06:53,959 --> 00:06:57,239 by the IMF it's called the world 156 00:06:55,519 --> 00:06:59,598 economic Outlook I think I mentioned it 157 00:06:57,240 --> 00:07:01,199 before and here you have some forecast 158 00:06:59,598 --> 00:07:04,560 you know well this is actually what 159 00:07:01,199 --> 00:07:08,759 happened so growth in the global economy 160 00:07:04,560 --> 00:07:11,439 was about 3.4% 2022 advanced economies 161 00:07:08,759 --> 00:07:13,720 grew at 2.7% emerging markets and 162 00:07:11,439 --> 00:07:16,000 developing economies at 163 00:07:13,720 --> 00:07:20,879 3.9% and then you see forast and the 164 00:07:16,000 --> 00:07:22,759 further out you go er um the okay the 165 00:07:20,879 --> 00:07:25,000 further out you go sort of it's less 166 00:07:22,759 --> 00:07:26,800 related to the current cycle is more 167 00:07:25,000 --> 00:07:27,959 related to what is structural the 168 00:07:26,800 --> 00:07:30,038 structural 169 00:07:27,959 --> 00:07:32,038 growth of the different parts of the 170 00:07:30,038 --> 00:07:35,120 world and you see that for 171 00:07:32,038 --> 00:07:37,478 2024 the global economy is projected 172 00:07:35,120 --> 00:07:38,918 expected to grow at around 3.1% this 173 00:07:37,478 --> 00:07:40,639 forecast were made before the mess 174 00:07:38,918 --> 00:07:42,598 Financial mess that we're going on right 175 00:07:40,639 --> 00:07:46,240 now so probably the next World economic 176 00:07:42,598 --> 00:07:48,199 Outlook will have at least for 2023 will 177 00:07:46,240 --> 00:07:51,519 will downgrade the growth probably not 178 00:07:48,199 --> 00:07:54,520 for 2024 but yes for 2023 anyways 179 00:07:51,519 --> 00:07:57,758 advanced economies expected to grow 180 00:07:54,519 --> 00:08:00,918 1.4% emerging markets at 181 00:07:57,759 --> 00:08:03,000 4.2% so 182 00:08:00,918 --> 00:08:05,079 these forecasts are based on on a 183 00:08:03,000 --> 00:08:07,399 combination of cyclical factors 184 00:08:05,079 --> 00:08:08,399 fluctuations of the short run medium run 185 00:08:07,399 --> 00:08:10,679 the kind of things we have been 186 00:08:08,399 --> 00:08:12,079 discussing up to now some economies will 187 00:08:10,680 --> 00:08:14,560 have to go through recession some 188 00:08:12,079 --> 00:08:17,598 economies are going through Booms that 189 00:08:14,560 --> 00:08:19,199 probably dominates 20 the forus on 2023 190 00:08:17,598 --> 00:08:21,560 but as I said before the further out you 191 00:08:19,199 --> 00:08:23,478 go the more the less relevant is the 192 00:08:21,560 --> 00:08:26,079 current business cycle and the more 193 00:08:23,478 --> 00:08:28,959 relevant is the structural trend of the 194 00:08:26,079 --> 00:08:31,158 different regions of the world okay so I 195 00:08:28,959 --> 00:08:33,559 would that in this when they formulated 196 00:08:31,158 --> 00:08:35,918 this forecast this is very much based on 197 00:08:33,559 --> 00:08:38,359 more longer run growth model the kind of 198 00:08:35,918 --> 00:08:41,038 models we're going to discuss now okay 199 00:08:38,360 --> 00:08:42,839 while this is probably totally dominated 200 00:08:41,038 --> 00:08:46,159 by the kind of things we discuss up to 201 00:08:42,839 --> 00:08:48,800 now okay 202 00:08:46,159 --> 00:08:51,719 um there are several things that that 203 00:08:48,799 --> 00:08:54,000 that are interesting here aside from 204 00:08:51,720 --> 00:08:56,440 sort of the the the 205 00:08:54,000 --> 00:08:59,000 fluctuations year to year one thing you 206 00:08:56,440 --> 00:09:00,079 can see for example is that regardless 207 00:08:59,000 --> 00:09:02,759 of year 208 00:09:00,078 --> 00:09:04,799 on average Emerging Markets tend to grow 209 00:09:02,759 --> 00:09:06,600 faster than develop economies advanced 210 00:09:04,799 --> 00:09:08,319 economies okay so one of the things we 211 00:09:06,600 --> 00:09:12,079 want to understand is why is that the 212 00:09:08,320 --> 00:09:13,680 case okay but that's is very clear here 213 00:09:12,078 --> 00:09:15,559 that's the first model we're going to 214 00:09:13,679 --> 00:09:17,319 look at which probably will happen on 215 00:09:15,559 --> 00:09:19,039 Wednesday we'll try to explain 216 00:09:17,320 --> 00:09:21,800 essentially that why is it that these 217 00:09:19,039 --> 00:09:25,240 guys tend to grow faster than the 218 00:09:21,799 --> 00:09:25,240 advanced economies 219 00:09:25,559 --> 00:09:30,359 okay so growth is important I mean the 220 00:09:28,720 --> 00:09:32,560 standing economic growth is hugely 221 00:09:30,360 --> 00:09:35,759 important for the weal for understanding 222 00:09:32,559 --> 00:09:39,399 sort of the health of an economy here 223 00:09:35,759 --> 00:09:44,720 you see this comes from the textbook er 224 00:09:39,399 --> 00:09:46,639 er the the US GDP in 20 20 225 00:09:44,720 --> 00:09:50,959 uh2 from 226 00:09:46,639 --> 00:09:53,519 1890 to to 2017 I think is this one the 227 00:09:50,958 --> 00:09:57,479 the end year the important thing to 228 00:09:53,519 --> 00:10:01,480 notice here is how large is the change 229 00:09:57,480 --> 00:10:04,480 in GDP in during the period I mean GDP 230 00:10:01,480 --> 00:10:09,440 here measuring the same prices so 20 231 00:10:04,480 --> 00:10:10,920 2012 prices is 50 times that in 1890 232 00:10:09,440 --> 00:10:12,720 that's a big thing I mean when we talk 233 00:10:10,919 --> 00:10:15,679 about business cycle fluctuations we're 234 00:10:12,720 --> 00:10:19,519 talking about in an economy like the US 235 00:10:15,679 --> 00:10:22,919 two two and a half% up 3% up and down 236 00:10:19,519 --> 00:10:25,519 this is 50 times so over longer period 237 00:10:22,919 --> 00:10:27,439 of time you can almost ignore the 238 00:10:25,519 --> 00:10:30,759 business cycle and it's all about that 239 00:10:27,440 --> 00:10:33,440 long run H trend 240 00:10:30,759 --> 00:10:36,200 here what is this episode so so you here 241 00:10:33,440 --> 00:10:37,959 if you if you look at this picture know 242 00:10:36,200 --> 00:10:40,278 especially the F out you are on the on 243 00:10:37,958 --> 00:10:41,319 the on the room what dominates here is 244 00:10:40,278 --> 00:10:43,879 clearly the 245 00:10:41,320 --> 00:10:45,440 trend the only action you see really 246 00:10:43,879 --> 00:10:50,039 significant action different from the 247 00:10:45,440 --> 00:10:50,040 trend is around here what happened 248 00:10:50,240 --> 00:10:54,919 there it's the Great Depression so even 249 00:10:53,200 --> 00:10:57,920 the Great Depression you know doesn't 250 00:10:54,919 --> 00:10:59,838 look that big relative to what the trend 251 00:10:57,919 --> 00:11:01,278 can do so 252 00:10:59,839 --> 00:11:03,279 of course it's very difficult to affect 253 00:11:01,278 --> 00:11:05,600 the trend of a country but the trend 254 00:11:03,278 --> 00:11:07,000 makes a huge difference for the welfare 255 00:11:05,600 --> 00:11:11,000 for 256 00:11:07,000 --> 00:11:12,600 the economic well-being of a 257 00:11:11,000 --> 00:11:17,078 country 258 00:11:12,600 --> 00:11:20,120 good now a lot of that is because also 259 00:11:17,078 --> 00:11:23,439 the US population grew up grew up grew 260 00:11:20,120 --> 00:11:26,120 up and grew a lot during this episode 261 00:11:23,440 --> 00:11:27,880 so often when you look at sort of long 262 00:11:26,120 --> 00:11:30,120 run Trends rather than looking at the 263 00:11:27,879 --> 00:11:33,679 level of GDP you tend to look at the 264 00:11:30,120 --> 00:11:35,480 level of GDP per person per capita or 265 00:11:33,679 --> 00:11:37,679 something like that and that picture is 266 00:11:35,480 --> 00:11:40,039 exactly the same pictures as the 267 00:11:37,679 --> 00:11:43,799 previous one but divided by population 268 00:11:40,039 --> 00:11:45,319 at each point in time okay and and and 269 00:11:43,799 --> 00:11:46,919 and that's an important over long 270 00:11:45,320 --> 00:11:49,278 periods of you at the business cycle 271 00:11:46,919 --> 00:11:51,639 frequency you can almost ignore changes 272 00:11:49,278 --> 00:11:53,679 in popul no Chang ination you can ignore 273 00:11:51,639 --> 00:11:55,278 completely unless you are in a war you 274 00:11:53,679 --> 00:11:57,799 can you worry about other things labor 275 00:11:55,278 --> 00:11:59,480 force participation and stuff like that 276 00:11:57,799 --> 00:12:01,559 but population is irrelevant that the 277 00:11:59,480 --> 00:12:03,680 business cycle growth is irrelevant at 278 00:12:01,559 --> 00:12:06,479 the business cycle frequency but not 279 00:12:03,679 --> 00:12:08,719 over long periods of time in this period 280 00:12:06,480 --> 00:12:11,759 here population in the US increased from 281 00:12:08,720 --> 00:12:13,720 63 million to 320 million so that's a 282 00:12:11,759 --> 00:12:17,360 lot more workers in principle that you 283 00:12:13,720 --> 00:12:20,160 have you know for that economy so a lot 284 00:12:17,360 --> 00:12:23,519 of that trend is explained by population 285 00:12:20,159 --> 00:12:26,399 growth and that's one of the reason 286 00:12:23,519 --> 00:12:29,399 sorry a lot of the trend in this picture 287 00:12:26,399 --> 00:12:30,679 here is explained by population growth 288 00:12:29,399 --> 00:12:32,879 that's one of the reasons we're in a 289 00:12:30,679 --> 00:12:34,359 tricky time in the global economy 290 00:12:32,879 --> 00:12:35,838 because there are many important regions 291 00:12:34,360 --> 00:12:38,039 of the world where population is no 292 00:12:35,839 --> 00:12:40,399 longer growing so we got used to a 293 00:12:38,039 --> 00:12:43,639 period in which population growth was 294 00:12:40,399 --> 00:12:45,720 very steady and high and now you know 295 00:12:43,639 --> 00:12:48,399 many parts of the world important parts 296 00:12:45,720 --> 00:12:53,160 of of the world have negative population 297 00:12:48,399 --> 00:12:56,159 growth Japan Korea China most of 298 00:12:53,159 --> 00:12:58,198 Continental Europe H even places in 299 00:12:56,159 --> 00:13:01,039 Latin America and so on so so this is a 300 00:12:58,198 --> 00:13:03,319 big change for the world 301 00:13:01,039 --> 00:13:05,480 but anyways during that period there was 302 00:13:03,320 --> 00:13:07,199 a lot of population growth and in the US 303 00:13:05,480 --> 00:13:09,720 in particular when again as I said 304 00:13:07,198 --> 00:13:12,319 before from 63 to 320 million so if you 305 00:13:09,720 --> 00:13:15,240 really want to measure sort of welfare 306 00:13:12,320 --> 00:13:16,519 of the economy how well how the 307 00:13:15,240 --> 00:13:19,360 well-being of 308 00:13:16,519 --> 00:13:21,078 individuals in in in in the US the 309 00:13:19,360 --> 00:13:24,240 previous picture is misleading because 310 00:13:21,078 --> 00:13:26,759 you have to yeah it's the final Pi is 50 311 00:13:24,240 --> 00:13:29,159 times larger than the first one than the 312 00:13:26,759 --> 00:13:31,759 beginning Pi but you have 320 million 313 00:13:29,159 --> 00:13:35,278 people to split it among as opposed to 314 00:13:31,759 --> 00:13:36,919 63 million so this picture captures that 315 00:13:35,278 --> 00:13:39,198 statistic that is often described when 316 00:13:36,919 --> 00:13:43,039 you talk about long run 317 00:13:39,198 --> 00:13:45,319 growth ER is GDP per person and you 318 00:13:43,039 --> 00:13:48,919 still see that what dominates this 319 00:13:45,320 --> 00:13:51,800 picture is a trend ER but the difference 320 00:13:48,919 --> 00:13:53,759 between this out out GDP per person in 321 00:13:51,799 --> 00:13:55,838 the US at the end of the sample versus 322 00:13:53,759 --> 00:13:58,639 the beginning of the sample is 10 to1 323 00:13:55,839 --> 00:14:00,560 not 50 to1 so it makes a difference 324 00:13:58,639 --> 00:14:02,799 population it's still big it's still 325 00:14:00,559 --> 00:14:05,000 what dominates this picture is that of 326 00:14:02,799 --> 00:14:07,559 course the Great Recession looks bigger 327 00:14:05,000 --> 00:14:09,278 now because you know you comparing it 328 00:14:07,559 --> 00:14:11,679 with with a number that grows by a 329 00:14:09,278 --> 00:14:14,198 factor of 10 not by a factor of 50 330 00:14:11,679 --> 00:14:16,239 that's so it looks bigger naturally know 331 00:14:14,198 --> 00:14:18,958 the same 30% decline output is a lot 332 00:14:16,240 --> 00:14:21,120 bigger when you're comparing it with 333 00:14:18,958 --> 00:14:23,879 the a factor of 10 than when you're 334 00:14:21,120 --> 00:14:27,679 comparing it with a factor of 50 but 335 00:14:23,879 --> 00:14:30,240 still it looks bigger but the picture is 336 00:14:27,679 --> 00:14:33,159 dominated by the 337 00:14:30,240 --> 00:14:35,159 so all this to say that we're going to 338 00:14:33,159 --> 00:14:36,879 study now is very important it's not 339 00:14:35,159 --> 00:14:39,159 what dominates the day-to-day news 340 00:14:36,879 --> 00:14:41,879 because it happens slowly and over time 341 00:14:39,159 --> 00:14:41,879 but it is very 342 00:14:43,399 --> 00:14:48,320 important so how do we measure these 343 00:14:45,839 --> 00:14:51,199 things well when you're looking within a 344 00:14:48,320 --> 00:14:54,278 country you do reasonably well not 345 00:14:51,198 --> 00:14:56,078 perfect but reasonably well and perhaps 346 00:14:54,278 --> 00:14:58,720 not over periods as long as I want I 347 00:14:56,078 --> 00:15:01,879 show you by looking at GDP per capita 348 00:14:58,720 --> 00:15:04,879 that's that's fine is you measure it 349 00:15:01,879 --> 00:15:06,480 real GDP per capita that's about fine 350 00:15:04,879 --> 00:15:09,198 but when you compare across different 351 00:15:06,480 --> 00:15:12,440 regions of the world and so on those 352 00:15:09,198 --> 00:15:17,838 comparisons is very misleading so to say 353 00:15:12,440 --> 00:15:21,440 that the US has um I don't know 354 00:15:17,839 --> 00:15:23,959 ER what is the US GDP per capita today 355 00:15:21,440 --> 00:15:28,040 in the US somebody should check it but 356 00:15:23,958 --> 00:15:31,039 but about maybe $70,000 something like 357 00:15:28,039 --> 00:15:34,838 that I don't know ER and then then then 358 00:15:31,039 --> 00:15:37,399 you see a another country that has say 359 00:15:34,839 --> 00:15:40,959 Italy $50,000 per 360 00:15:37,399 --> 00:15:43,440 capita that comparison is not that 361 00:15:40,958 --> 00:15:45,000 meaningful it's indicative of something 362 00:15:43,440 --> 00:15:46,160 but it's not completely meaningful and 363 00:15:45,000 --> 00:15:48,600 I'm going to show you an example which 364 00:15:46,159 --> 00:15:51,360 is much more extreme than that but the 365 00:15:48,600 --> 00:15:53,120 reason is not very meaningful is 366 00:15:51,360 --> 00:15:55,879 essentially because the prices are not 367 00:15:53,120 --> 00:15:59,560 the same across different parts of the 368 00:15:55,879 --> 00:16:01,360 world so we have a method to to to to do 369 00:15:59,559 --> 00:16:03,359 that to to be able to compare across 370 00:16:01,360 --> 00:16:05,480 countries and again even for a one a 371 00:16:03,360 --> 00:16:09,159 given country over long long period of 372 00:16:05,480 --> 00:16:12,120 time we make a correction to the GDP 373 00:16:09,159 --> 00:16:13,600 numbers we have and we make we call them 374 00:16:12,120 --> 00:16:16,799 we correct them by what is called the 375 00:16:13,600 --> 00:16:19,120 PPP purchasing power parity and I'll 376 00:16:16,799 --> 00:16:23,318 explain what that is okay so whenever 377 00:16:19,120 --> 00:16:25,120 almost whenever you see comparisons of a 378 00:16:23,318 --> 00:16:27,399 GDP per capita across countries when 379 00:16:25,120 --> 00:16:31,278 somebody's doing a growth analysis is 380 00:16:27,399 --> 00:16:34,519 going to be PPP adjusted okay now let me 381 00:16:31,278 --> 00:16:36,159 explain the logic of 382 00:16:34,519 --> 00:16:39,000 PB 383 00:16:36,159 --> 00:16:41,679 um and and and again I said within the 384 00:16:39,000 --> 00:16:44,318 same country over periods perhaps not 385 00:16:41,679 --> 00:16:48,359 300 years but over periods of 40 years 386 00:16:44,318 --> 00:16:50,399 it's reasonable H to use just real GDP 387 00:16:48,360 --> 00:16:53,560 but when you start comparing sort of you 388 00:16:50,399 --> 00:16:56,278 know bana versus the US it gets a lot 389 00:16:53,559 --> 00:16:58,439 tricky trickier because there's a lot of 390 00:16:56,278 --> 00:17:01,958 goods that are a lot cheaper in poorer 391 00:16:58,440 --> 00:17:03,920 countries in particular food okay and 392 00:17:01,958 --> 00:17:05,159 and so so you have to be careful with 393 00:17:03,919 --> 00:17:07,678 those comparisons so I'm going to give 394 00:17:05,160 --> 00:17:09,759 you this example which is somewhat 395 00:17:07,679 --> 00:17:12,759 hypothetical but the numbers are not 396 00:17:09,759 --> 00:17:15,879 crazy so suppose you have a a two 397 00:17:12,759 --> 00:17:18,879 economies the US and Russia 398 00:17:15,880 --> 00:17:18,880 and 399 00:17:20,199 --> 00:17:25,640 um anyways 400 00:17:22,720 --> 00:17:29,200 ER and suppose that that in both 401 00:17:25,640 --> 00:17:32,520 economies ER households consume houses 402 00:17:29,200 --> 00:17:35,400 and firms consume cars and 403 00:17:32,519 --> 00:17:37,319 food okay and suppose that the average 404 00:17:35,400 --> 00:17:41,120 consumer in the US buys one car a year 405 00:17:37,319 --> 00:17:44,639 for $10,000 and a bundle of food for 406 00:17:41,119 --> 00:17:46,839 $10,000 as well okay so the total 407 00:17:44,640 --> 00:17:49,720 expenditure in consumption for this 408 00:17:46,839 --> 00:17:53,000 household on average is about $20,000 a 409 00:17:49,720 --> 00:17:55,519 year that's what a US household consumes 410 00:17:53,000 --> 00:17:59,119 these numbers are fantasy numbers but 411 00:17:55,519 --> 00:18:00,158 the big picture is not that fantasy 412 00:17:59,119 --> 00:18:03,279 ER 413 00:18:00,159 --> 00:18:07,600 Russia the average consumer buys 414 00:18:03,279 --> 00:18:10,079 0.07 cars a year for 40,000 rubles and 415 00:18:07,599 --> 00:18:12,480 the same bundle of food that in the US 416 00:18:10,079 --> 00:18:14,639 okay same assume that same bundle of 417 00:18:12,480 --> 00:18:17,960 food goes for 880,000 418 00:18:14,640 --> 00:18:21,600 rubles so the total expenditure of this 419 00:18:17,960 --> 00:18:24,880 H average household in Russia is 420 00:18:21,599 --> 00:18:27,558 120,000 rubles suppose that exchange is 421 00:18:24,880 --> 00:18:31,480 60 rubles per dollar this thing has 422 00:18:27,558 --> 00:18:33,798 moved a lot recent times but suppose 423 00:18:31,480 --> 00:18:36,919 that's the the number of rubles per 424 00:18:33,798 --> 00:18:38,918 dollar so you divide $120,000 and you 425 00:18:36,919 --> 00:18:41,919 want to convert them into Dollars you 426 00:18:38,919 --> 00:18:43,799 divide the 120,000 rubles by 60,000 427 00:18:41,919 --> 00:18:45,440 rubles per dollar and then you get how 428 00:18:43,798 --> 00:18:48,798 much the Russians spend a Russian 429 00:18:45,440 --> 00:18:51,320 household on average spends on on on 430 00:18:48,798 --> 00:18:54,839 consumption in a year and and it's 431 00:18:51,319 --> 00:18:58,038 $2,000 a year okay so here you have 432 00:18:54,839 --> 00:18:59,240 120,000 divided by 60 is 2,000 that's 433 00:18:58,038 --> 00:19:01,798 the number of dollar 434 00:18:59,240 --> 00:19:04,200 that an average household in Russia 435 00:19:01,798 --> 00:19:06,759 consumes so the question 436 00:19:04,200 --> 00:19:10,000 is you have a US household spends 437 00:19:06,759 --> 00:19:13,599 $20,000 a year a Russian household 438 00:19:10,000 --> 00:19:16,400 spends $22,000 a year and the question 439 00:19:13,599 --> 00:19:18,399 is then is Russia 10 times poorer than 440 00:19:16,400 --> 00:19:20,360 the 441 00:19:18,400 --> 00:19:22,919 US 442 00:19:20,359 --> 00:19:26,798 okay that if you were to compare real 443 00:19:22,919 --> 00:19:29,240 GDP that would be answer so yeah they 444 00:19:26,798 --> 00:19:30,918 and it's true if you look at a again in 445 00:19:29,240 --> 00:19:33,679 this 446 00:19:30,919 --> 00:19:36,159 example if you look at the at the real 447 00:19:33,679 --> 00:19:38,640 GDP numbers of on the same year 448 00:19:36,159 --> 00:19:40,159 converted all into dollars that answer 449 00:19:38,640 --> 00:19:42,400 is 450 00:19:40,159 --> 00:19:44,000 correct but it doesn't represent the 451 00:19:42,400 --> 00:19:45,679 point is that it doesn't represent 452 00:19:44,000 --> 00:19:48,400 really The Well beinging of the average 453 00:19:45,679 --> 00:19:52,400 household in Russia for this reason at 454 00:19:48,400 --> 00:19:56,320 least why not well 455 00:19:52,400 --> 00:19:59,919 let's what you ultimately matter is how 456 00:19:56,319 --> 00:20:02,359 much real Goods the house 457 00:19:59,919 --> 00:20:03,840 consumes that's what really matters I 458 00:20:02,359 --> 00:20:06,158 mean if you live in a country where the 459 00:20:03,839 --> 00:20:08,079 price of everything is zero your 460 00:20:06,159 --> 00:20:09,200 consumption expenditure consumption will 461 00:20:08,079 --> 00:20:12,319 be 462 00:20:09,200 --> 00:20:14,080 zero but that doesn't mean that you are 463 00:20:12,319 --> 00:20:16,000 as unhappy as somebody that consumes 464 00:20:14,079 --> 00:20:18,639 zero you're consuming whatever it is it 465 00:20:16,000 --> 00:20:20,519 happens the prices tend to be very low 466 00:20:18,640 --> 00:20:22,520 and that's essentially the story here as 467 00:20:20,519 --> 00:20:24,918 I said before it tends to be the case 468 00:20:22,519 --> 00:20:28,240 that in poorer countries a lot of things 469 00:20:24,919 --> 00:20:30,480 are cheaper there is certain very high 470 00:20:28,240 --> 00:20:32,599 tech things that that are not even 471 00:20:30,480 --> 00:20:34,798 consumed in poorer countries so you have 472 00:20:32,599 --> 00:20:36,519 to adjust for that as well but a lot of 473 00:20:34,798 --> 00:20:39,480 the regular things the bulk of the 474 00:20:36,519 --> 00:20:41,918 purchases tend to be a lot cheaper in 475 00:20:39,480 --> 00:20:44,720 poorer countries and that's exactly what 476 00:20:41,919 --> 00:20:45,840 is behind the reason why in this example 477 00:20:44,720 --> 00:20:48,159 the answer is 478 00:20:45,839 --> 00:20:50,199 no it's not true that the Russians are 479 00:20:48,159 --> 00:20:52,840 10 time that Russian household in this 480 00:20:50,200 --> 00:20:55,600 example is 10 times poorer than the US 481 00:20:52,839 --> 00:20:59,199 let's check it so that's our 482 00:20:55,599 --> 00:21:01,439 example and I said no so fast 483 00:20:59,200 --> 00:21:03,440 let's use so assume that the goods are 484 00:21:01,440 --> 00:21:06,480 the same so the cars that the Russians 485 00:21:03,440 --> 00:21:09,759 buy is the same as the as the cars that 486 00:21:06,480 --> 00:21:13,880 the US households buy that was 487 00:21:09,759 --> 00:21:15,679 truer a few months ago than now but but 488 00:21:13,880 --> 00:21:18,840 assume that's the case it's just that 489 00:21:15,679 --> 00:21:21,480 the Russians by you know change their 490 00:21:18,839 --> 00:21:23,359 cars less frequently in this example the 491 00:21:21,480 --> 00:21:26,120 US household is changing the car once a 492 00:21:23,359 --> 00:21:28,959 year while while while the Russians are 493 00:21:26,119 --> 00:21:31,918 changing the car you know less than once 494 00:21:28,960 --> 00:21:34,880 every 10 year one every 15 years or 495 00:21:31,919 --> 00:21:37,440 so let's assume also that the the bundle 496 00:21:34,880 --> 00:21:40,600 of the of food is exactly the same in 497 00:21:37,440 --> 00:21:44,600 both Place places so since the car is 498 00:21:40,599 --> 00:21:47,839 the same and the and the and the and the 499 00:21:44,599 --> 00:21:49,879 bundle of food is the same I can use us 500 00:21:47,839 --> 00:21:53,119 prices to 501 00:21:49,880 --> 00:21:56,559 measure Uh Russian consumption and 502 00:21:53,119 --> 00:21:59,439 that's is comparable to what us 503 00:21:56,558 --> 00:22:00,879 consumption is because I'm taking I'm 504 00:21:59,440 --> 00:22:02,960 trying to convert the goods they're 505 00:22:00,880 --> 00:22:05,799 consuming into something is comparable 506 00:22:02,960 --> 00:22:08,440 to what the US consumes since the goods 507 00:22:05,798 --> 00:22:10,038 themselves are the same if I value them 508 00:22:08,440 --> 00:22:12,640 at the same price either of the two 509 00:22:10,038 --> 00:22:14,038 prices but at the same prices then I'm 510 00:22:12,640 --> 00:22:17,360 going to be able to make the comparison 511 00:22:14,038 --> 00:22:20,839 I really want that's what purchase power 512 00:22:17,359 --> 00:22:22,639 PVP adjustment means okay so look at our 513 00:22:20,839 --> 00:22:26,199 particular example here the Russian 514 00:22:22,640 --> 00:22:29,240 would household would be consuming 0.07 515 00:22:26,200 --> 00:22:32,120 cars times 10,000 dollar which is the 516 00:22:29,240 --> 00:22:36,880 price of a car plus one unit of of the 517 00:22:32,119 --> 00:22:39,959 bundle of of of of food and the price us 518 00:22:36,880 --> 00:22:41,799 price is 10,000 for that so the total 519 00:22:39,960 --> 00:22:44,960 consumption of the household PPP 520 00:22:41,798 --> 00:22:49,480 adjusted the Russian household is 521 00:22:44,960 --> 00:22:53,880 10,700 okay that's not one10 it's 522 00:22:49,480 --> 00:22:55,960 53% of us consumption so true Russian 523 00:22:53,880 --> 00:22:58,960 household is poorer than than than than 524 00:22:55,960 --> 00:23:02,640 an average US household but it's not 10 525 00:22:58,960 --> 00:23:05,200 poor no it has it's 526 00:23:02,640 --> 00:23:10,880 a is 527 00:23:05,200 --> 00:23:13,080 53% uh as rich as the US household okay 528 00:23:10,880 --> 00:23:15,400 and so this is big and all the numbers 529 00:23:13,079 --> 00:23:16,918 I'm going to show you next especially 530 00:23:15,400 --> 00:23:18,720 when we compare across sort of countries 531 00:23:16,919 --> 00:23:20,919 that are very different in terms of 532 00:23:18,720 --> 00:23:23,919 level of development and so on have 533 00:23:20,919 --> 00:23:25,400 these kind of Corrections built in okay 534 00:23:23,919 --> 00:23:27,278 if you need the data for these kind of 535 00:23:25,400 --> 00:23:29,200 things for whatever reason you find them 536 00:23:27,278 --> 00:23:30,960 in what is called the pen tables the pen 537 00:23:29,200 --> 00:23:33,240 tables essentially collects all the 538 00:23:30,960 --> 00:23:34,480 national accounts of all places and 539 00:23:33,240 --> 00:23:36,240 makes these 540 00:23:34,480 --> 00:23:39,000 Corrections the problem is they don't 541 00:23:36,240 --> 00:23:40,640 have update them very frequently but but 542 00:23:39,000 --> 00:23:42,839 if you look in Fred for example which 543 00:23:40,640 --> 00:23:45,919 you use in one of the p sets there will 544 00:23:42,839 --> 00:23:49,759 be numbers for a few countries that have 545 00:23:45,919 --> 00:23:49,759 this um PPP 546 00:23:49,798 --> 00:23:54,599 adjustment okay so that that's that's 547 00:23:53,119 --> 00:23:56,038 going to remain in the background now 548 00:23:54,599 --> 00:23:57,839 but I just wanted to tell you how how 549 00:23:56,038 --> 00:23:59,679 you construct numbers when you want to 550 00:23:57,839 --> 00:24:00,918 talk about long run and comparison 551 00:23:59,679 --> 00:24:04,880 across 552 00:24:00,919 --> 00:24:08,400 countries first set of numbers here look 553 00:24:04,880 --> 00:24:10,760 at these are obviously all today at 554 00:24:08,400 --> 00:24:13,519 least develop economies look at the 555 00:24:10,759 --> 00:24:16,000 growth between 1950 2017 obviously the 556 00:24:13,519 --> 00:24:17,679 war created a big mess there but before 557 00:24:16,000 --> 00:24:20,159 that so let's start from 558 00:24:17,679 --> 00:24:22,798 1950 and what you see here is you know 559 00:24:20,159 --> 00:24:25,919 France on average during this period 560 00:24:22,798 --> 00:24:27,038 France grew 2017 I think is the last yes 561 00:24:25,919 --> 00:24:29,440 it's the last 562 00:24:27,038 --> 00:24:31,679 year I think they were recently updated 563 00:24:29,440 --> 00:24:33,480 but at least when the book was published 564 00:24:31,679 --> 00:24:36,278 that was the last year they had pen 565 00:24:33,480 --> 00:24:40,278 tables for but 566 00:24:36,278 --> 00:24:42,159 um er France grew on average 2.6% per 567 00:24:40,278 --> 00:24:44,679 year on average they also had a business 568 00:24:42,159 --> 00:24:47,520 cycle and so on but on average 2.6% per 569 00:24:44,679 --> 00:24:49,320 year Japan during this period grew by 570 00:24:47,519 --> 00:24:53,798 four four 571 00:24:49,319 --> 00:24:56,599 4.1% the UK 2.1% the US 2% so the 572 00:24:53,798 --> 00:25:00,798 developed World essentially grew around 573 00:24:56,599 --> 00:25:03,639 2.7% on average during this 574 00:25:00,798 --> 00:25:07,440 period look at the effect that that this 575 00:25:03,640 --> 00:25:10,360 has on on the level of GDP per per per 576 00:25:07,440 --> 00:25:13,000 per person and all this PPP 577 00:25:10,359 --> 00:25:17,079 adjusted ER for the case of 578 00:25:13,000 --> 00:25:20,798 France 5.6 times so they started with 579 00:25:17,079 --> 00:25:24,918 $7,000 and they were close to $40,000 in 580 00:25:20,798 --> 00:25:28,599 2017 so the r is RA 581 00:25:24,919 --> 00:25:31,360 5.6 look at the US the US is 2% and that 582 00:25:28,599 --> 00:25:33,240 ratio is is still richer than France per 583 00:25:31,359 --> 00:25:36,959 per person in 584 00:25:33,240 --> 00:25:39,240 2017 but but the ratio of that to that 585 00:25:36,960 --> 00:25:40,759 is smaller than that so over a long 586 00:25:39,240 --> 00:25:42,960 period of time that's what a trend in 587 00:25:40,759 --> 00:25:44,679 the picture capture a small difference 588 00:25:42,960 --> 00:25:46,679 in the rate of growth if they are 589 00:25:44,679 --> 00:25:49,000 sustained for a long period of time can 590 00:25:46,679 --> 00:25:54,600 make quite a bit of difference for the 591 00:25:49,000 --> 00:25:56,919 change in in GDP okay and so what do you 592 00:25:54,599 --> 00:25:59,480 what is the first what is the p is I 593 00:25:56,919 --> 00:26:01,038 mean let's find the pattern here here 594 00:25:59,480 --> 00:26:04,720 there's a very clear pattern in that 595 00:26:01,038 --> 00:26:07,278 picture in that table what is it do you 596 00:26:04,720 --> 00:26:07,278 can you spot 597 00:26:15,919 --> 00:26:20,679 it I hadn't 598 00:26:18,200 --> 00:26:22,720 actually realized it when I was looking 599 00:26:20,679 --> 00:26:24,360 at my notes and then I realized is very 600 00:26:22,720 --> 00:26:26,558 clear in this table that's the reason I 601 00:26:24,359 --> 00:26:30,240 added this line I updated the slide this 602 00:26:26,558 --> 00:26:30,240 morning do you see a pattern 603 00:26:34,240 --> 00:26:40,038 yes the higher growth rate have a higher 604 00:26:37,640 --> 00:26:41,240 multiple yeah well that's yes that but 605 00:26:40,038 --> 00:26:43,640 that's 606 00:26:41,240 --> 00:26:45,558 math okay which is so it's a true 607 00:26:43,640 --> 00:26:48,640 statement but that's just 608 00:26:45,558 --> 00:26:49,639 math there's an economic thing that that 609 00:26:48,640 --> 00:26:53,038 that I want 610 00:26:49,640 --> 00:26:54,480 to so so you're right but but I want 611 00:26:53,038 --> 00:26:58,480 they should have clarified there's an 612 00:26:54,480 --> 00:26:58,480 economic pattern there 613 00:27:03,880 --> 00:27:10,760 let let me simplify just look at these 614 00:27:05,839 --> 00:27:13,439 two columns because a higher number here 615 00:27:10,759 --> 00:27:15,640 simply sorry a higher number here simply 616 00:27:13,440 --> 00:27:18,038 means that you had a higher rate of 617 00:27:15,640 --> 00:27:20,360 growth that's your math fact so ignore 618 00:27:18,038 --> 00:27:23,158 this column what I suggest is that you 619 00:27:20,359 --> 00:27:23,158 just look at these two 620 00:27:24,278 --> 00:27:29,599 columns do you see a 621 00:27:27,159 --> 00:27:31,520 pattern just look at these two columns 622 00:27:29,599 --> 00:27:33,119 this one in a sense just repeats 623 00:27:31,519 --> 00:27:35,440 information that is here for the reason 624 00:27:33,119 --> 00:27:38,678 you describe but just look at these two 625 00:27:35,440 --> 00:27:38,679 columns is there a pattern 626 00:27:40,398 --> 00:27:45,918 there exactly very important Richard 627 00:27:44,240 --> 00:27:49,000 countri sent to grow slower the richest 628 00:27:45,919 --> 00:27:50,720 country here is the US had the lowest 629 00:27:49,000 --> 00:27:54,720 rate of growth on 630 00:27:50,720 --> 00:27:58,200 average the poorest was Japan there and 631 00:27:54,720 --> 00:27:59,640 they had the highest rate of growth okay 632 00:27:58,200 --> 00:28:00,960 so that's a very important correlation 633 00:27:59,640 --> 00:28:02,480 and again the first model we're going to 634 00:28:00,960 --> 00:28:05,159 see of economic growth is going to 635 00:28:02,480 --> 00:28:07,360 explain that correlation why is that we 636 00:28:05,159 --> 00:28:09,799 see 637 00:28:07,359 --> 00:28:11,079 that those were for five economy you 638 00:28:09,798 --> 00:28:13,480 could say it's an accident but look at 639 00:28:11,079 --> 00:28:16,158 this this this is just a this is rich 640 00:28:13,480 --> 00:28:18,278 countries in general since 1950s and you 641 00:28:16,159 --> 00:28:19,880 look at here in this axis you have the 642 00:28:18,278 --> 00:28:23,640 annual rate of growth the average rate 643 00:28:19,880 --> 00:28:26,519 of growth and here the GDP per person in 644 00:28:23,640 --> 00:28:29,399 1950 so at the beginning of the sample 645 00:28:26,519 --> 00:28:32,159 1950 these countries had have this level 646 00:28:29,398 --> 00:28:36,038 of GDP per capita and then here is the 647 00:28:32,159 --> 00:28:39,000 rate of growth on average from 1950 to 648 00:28:36,038 --> 00:28:42,599 1987 and it's very clear there that 649 00:28:39,000 --> 00:28:44,558 there's a downward sloping pattern no so 650 00:28:42,599 --> 00:28:46,879 that's the same fact now for many more 651 00:28:44,558 --> 00:28:48,759 countries there's a downward sloping 652 00:28:46,880 --> 00:28:51,039 relationship really the richest 653 00:28:48,759 --> 00:28:52,679 countries tend to grow much slower than 654 00:28:51,038 --> 00:28:54,319 the countries were poorer at the 655 00:28:52,679 --> 00:28:56,000 beginning of the 656 00:28:54,319 --> 00:28:59,278 sample 657 00:28:56,000 --> 00:29:02,798 okay there are some interesting 658 00:28:59,278 --> 00:29:05,119 liers like Mexico and and is an 659 00:29:02,798 --> 00:29:08,918 interesting in itself I'm not going to 660 00:29:05,119 --> 00:29:12,398 say a lot about why that's the case 661 00:29:08,919 --> 00:29:14,840 but but but let me for now stick to the 662 00:29:12,398 --> 00:29:17,798 to the pattern the dominant pattern 663 00:29:14,839 --> 00:29:19,480 which is is a downward sloping 664 00:29:17,798 --> 00:29:22,519 relationship that's another way of 665 00:29:19,480 --> 00:29:25,399 seeing it and this is for just a bigger 666 00:29:22,519 --> 00:29:29,038 variety of countries I have Botana China 667 00:29:25,398 --> 00:29:32,278 Thailand and so on and and you see here 668 00:29:29,038 --> 00:29:33,278 GDP at the beginning of the 1950 and GDP 669 00:29:32,278 --> 00:29:35,640 rate 670 00:29:33,278 --> 00:29:37,079 2018 and the pattern here which is 671 00:29:35,640 --> 00:29:38,960 essentially a repetition of the pattern 672 00:29:37,079 --> 00:29:44,918 that I showed you before is that there 673 00:29:38,960 --> 00:29:47,240 is much more compression here than 674 00:29:44,919 --> 00:29:50,559 here how can you have more compression 675 00:29:47,240 --> 00:29:52,839 here than here well because there is 676 00:29:50,558 --> 00:29:55,240 some sort of convergence no there's a 677 00:29:52,839 --> 00:29:58,079 sense of convergence is that those that 678 00:29:55,240 --> 00:30:00,359 were poorer tend to grow a little faster 679 00:29:58,079 --> 00:30:02,158 than those that were richer and 680 00:30:00,359 --> 00:30:04,240 therefore they tend to converge to each 681 00:30:02,159 --> 00:30:06,399 other so that's the the point I'm 682 00:30:04,240 --> 00:30:10,558 highlighting here a lot of this persion 683 00:30:06,398 --> 00:30:13,278 1950 much less isers in 2018 that means 684 00:30:10,558 --> 00:30:17,119 that on average the poorer countries are 685 00:30:13,278 --> 00:30:17,119 growing faster than the Richer 686 00:30:19,200 --> 00:30:26,679 countries and again all this is per 687 00:30:21,398 --> 00:30:26,678 capita PPP adjust and all that okay 688 00:30:30,319 --> 00:30:34,519 this 689 00:30:31,839 --> 00:30:37,918 picture again sort of makes the the 690 00:30:34,519 --> 00:30:40,519 point but now it takes a much many more 691 00:30:37,919 --> 00:30:43,960 countries and you can what the point of 692 00:30:40,519 --> 00:30:46,200 this picture is in the book is is is to 693 00:30:43,960 --> 00:30:49,000 highlight that it's a little messy the 694 00:30:46,200 --> 00:30:52,519 picture but to highlight that if you 695 00:30:49,000 --> 00:30:55,398 look in different regions oecd a major 696 00:30:52,519 --> 00:30:57,638 the major economies H tend to the 697 00:30:55,398 --> 00:31:00,518 pattern I show you holds if you look at 698 00:30:57,638 --> 00:31:03,038 only isolate only the blue the blue 699 00:31:00,519 --> 00:31:06,919 squares you tend to see that negative 700 00:31:03,038 --> 00:31:11,000 relationship if you look at within 701 00:31:06,919 --> 00:31:13,639 Asia it's also it's a little bit noisier 702 00:31:11,000 --> 00:31:15,440 but you also tend to see a negative 703 00:31:13,638 --> 00:31:17,918 relationship 704 00:31:15,440 --> 00:31:21,960 okay if you look at 705 00:31:17,919 --> 00:31:23,679 Africa that relationship is lost 706 00:31:21,960 --> 00:31:27,519 completely 707 00:31:23,679 --> 00:31:28,798 okay so so when you look at the world as 708 00:31:27,519 --> 00:31:30,519 a whole 709 00:31:28,798 --> 00:31:32,558 the picture is not as neat as the one I 710 00:31:30,519 --> 00:31:33,960 show you because there are certain 711 00:31:32,558 --> 00:31:35,720 pockets of the world that are not 712 00:31:33,960 --> 00:31:38,360 behaving according to the kind of mods I 713 00:31:35,720 --> 00:31:39,839 want I discuss in the next few lectures 714 00:31:38,359 --> 00:31:42,000 and the reason they're not behaving is 715 00:31:39,839 --> 00:31:45,359 entirely it's almost outside economics 716 00:31:42,000 --> 00:31:47,599 it has it's political conflicts Wars and 717 00:31:45,359 --> 00:31:49,359 things of that nature which continuously 718 00:31:47,599 --> 00:31:50,719 disrupt sort of the economic forces that 719 00:31:49,359 --> 00:31:53,398 I'm going to highlight in the next few 720 00:31:50,720 --> 00:31:56,720 lectures 721 00:31:53,398 --> 00:31:58,599 okay so that's a different different 722 00:31:56,720 --> 00:32:01,278 different issue where going to be about 723 00:31:58,599 --> 00:32:06,959 the all the moles I'll show you next are 724 00:32:01,278 --> 00:32:06,960 about the blue and the and the 725 00:32:07,319 --> 00:32:13,918 green squares and and and triangles 726 00:32:10,599 --> 00:32:13,918 there not about the red 727 00:32:14,798 --> 00:32:20,599 ones what about so I look I show you 728 00:32:17,759 --> 00:32:23,200 what happens across countries over over 729 00:32:20,599 --> 00:32:26,678 certain period of time which is long but 730 00:32:23,200 --> 00:32:29,798 not that long here you see what happens 731 00:32:26,679 --> 00:32:31,720 in longer here history there are two 732 00:32:29,798 --> 00:32:35,558 patterns that I like to highlight here 733 00:32:31,720 --> 00:32:37,839 is that H first for a while sort of you 734 00:32:35,558 --> 00:32:40,480 you didn't see much but but you tend to 735 00:32:37,839 --> 00:32:45,038 see a sort of a big acceleration in the 736 00:32:40,480 --> 00:32:48,599 Western World especially around the the 737 00:32:45,038 --> 00:32:50,158 1950s or so okay so so clearly the 738 00:32:48,599 --> 00:32:52,519 Western world was growing faster than 739 00:32:50,159 --> 00:32:56,360 the rest of the world H the Western 740 00:32:52,519 --> 00:32:59,839 Hemisphere this is a um um world Bank 741 00:32:56,359 --> 00:32:59,839 IFI type type 742 00:33:01,200 --> 00:33:05,798 um 743 00:33:03,159 --> 00:33:07,919 grouping and and you see that there's a 744 00:33:05,798 --> 00:33:12,119 very fast acceleration in growth in this 745 00:33:07,919 --> 00:33:14,240 episode here Western Europe H was also 746 00:33:12,119 --> 00:33:16,079 flattish and then picked up very 747 00:33:14,240 --> 00:33:18,558 strongly there and you see the different 748 00:33:16,079 --> 00:33:21,480 regions of the world and again you see 749 00:33:18,558 --> 00:33:26,879 the sub Sahara Africa region that sort 750 00:33:21,480 --> 00:33:26,880 of has hasn't really picked up okay 751 00:33:28,599 --> 00:33:34,079 much longer history well that's the way 752 00:33:31,440 --> 00:33:36,639 it looks for the world as a whole 753 00:33:34,079 --> 00:33:38,798 okay you know exponential pictures tend 754 00:33:36,638 --> 00:33:41,959 to look like that but but this is more 755 00:33:38,798 --> 00:33:44,240 dramatic than exponential and again what 756 00:33:41,960 --> 00:33:46,840 happens is 757 00:33:44,240 --> 00:33:49,679 that what happen here is is going to be 758 00:33:46,839 --> 00:33:51,480 very different from from the kind of 759 00:33:49,679 --> 00:33:53,759 mods I'll describe 760 00:33:51,480 --> 00:33:55,480 next this period here is mostly 761 00:33:53,759 --> 00:33:58,558 dominated by what's called sort of the 762 00:33:55,480 --> 00:34:01,440 malthusian era which is essentially 763 00:33:58,558 --> 00:34:03,759 people live population grew and so on 764 00:34:01,440 --> 00:34:06,679 depending on how good was the the 765 00:34:03,759 --> 00:34:07,960 harvest that year and so on no so so you 766 00:34:06,679 --> 00:34:10,200 had this mod in which you know his 767 00:34:07,960 --> 00:34:13,079 population grew faster that was a main 768 00:34:10,199 --> 00:34:15,000 driver of of of growth well but you know 769 00:34:13,079 --> 00:34:17,280 there wasn't enough food to sustain a a 770 00:34:15,000 --> 00:34:18,878 higher population and then you stay 771 00:34:17,280 --> 00:34:21,760 soort of there was a fight between food 772 00:34:18,878 --> 00:34:23,559 and and and people and and and no much 773 00:34:21,760 --> 00:34:26,960 space for most people were in 774 00:34:23,559 --> 00:34:28,679 agriculture and and the and and and 775 00:34:26,960 --> 00:34:31,320 there wasn't sort of 776 00:34:28,679 --> 00:34:33,159 much to build on nowadays there are 777 00:34:31,320 --> 00:34:36,119 pocket in the world and we had the 778 00:34:33,159 --> 00:34:38,358 severe situations during covid but food 779 00:34:36,119 --> 00:34:41,838 is not really a constraint for growth 780 00:34:38,358 --> 00:34:44,679 for the world as a whole 781 00:34:41,838 --> 00:34:47,358 okay and but you see 782 00:34:44,679 --> 00:34:49,878 so in other words had you taken this 783 00:34:47,358 --> 00:34:51,878 course in 20 in year 1000 or in the 784 00:34:49,878 --> 00:34:54,000 Renaissance nobody would have talked 785 00:34:51,878 --> 00:34:56,960 about growth it's not something that 786 00:34:54,000 --> 00:34:59,159 happened really it's it's a very modern 787 00:34:56,960 --> 00:35:02,679 thing to think about these pictures with 788 00:34:59,159 --> 00:35:05,118 these long Trends and so on 789 00:35:02,679 --> 00:35:06,598 okay I mean there you would have talked 790 00:35:05,119 --> 00:35:09,079 about a lot more interesting things than 791 00:35:06,599 --> 00:35:12,280 this but but not not about growth that's 792 00:35:09,079 --> 00:35:13,839 for sure and growth the last point I I 793 00:35:12,280 --> 00:35:15,359 think I want to make about this is it 794 00:35:13,838 --> 00:35:17,320 makes a big 795 00:35:15,358 --> 00:35:21,199 difference I don't know if you can read 796 00:35:17,320 --> 00:35:23,680 that I I can't but er um what I have 797 00:35:21,199 --> 00:35:28,159 here is GDP per capita in 798 00:35:23,679 --> 00:35:30,358 1950 versus GDP per capita in 2016 799 00:35:28,159 --> 00:35:33,239 and you have this isoquants here you 800 00:35:30,358 --> 00:35:35,559 move you as you move up so this line 801 00:35:33,239 --> 00:35:38,959 here is what happens to countries that 802 00:35:35,559 --> 00:35:40,920 is a 45 degree line so if you are on the 803 00:35:38,960 --> 00:35:43,199 45 degree line means that you haven't 804 00:35:40,920 --> 00:35:45,920 grown at all during this period no 805 00:35:43,199 --> 00:35:48,838 because that means that your GDP per 806 00:35:45,920 --> 00:35:52,079 capita 1950 is the same as you g GDP per 807 00:35:48,838 --> 00:35:54,960 capita in 2016 that means on average you 808 00:35:52,079 --> 00:35:57,680 grow okay but as I keep moving these 809 00:35:54,960 --> 00:35:58,960 lines up means you grew faster and fter 810 00:35:57,679 --> 00:36:03,078 faster and 811 00:35:58,960 --> 00:36:05,280 faster okay so and if you if you move 812 00:36:03,079 --> 00:36:07,318 along this line here that means you have 813 00:36:05,280 --> 00:36:10,280 negative growth on average during that 814 00:36:07,318 --> 00:36:13,719 period okay so each of these lines 815 00:36:10,280 --> 00:36:17,280 represents multiples so I think this is 816 00:36:13,719 --> 00:36:19,318 for example this top line here is 30 817 00:36:17,280 --> 00:36:21,760 times richer these are guys that grew 818 00:36:19,318 --> 00:36:23,838 very very fast yeah you I cannot read 819 00:36:21,760 --> 00:36:24,960 either but I I sort of know who is in 820 00:36:23,838 --> 00:36:26,559 each 821 00:36:24,960 --> 00:36:30,358 Place 822 00:36:26,559 --> 00:36:36,279 h this is an example here this is 823 00:36:30,358 --> 00:36:38,880 Taiwan okay this is Taiwan and H this is 824 00:36:36,280 --> 00:36:41,319 Singapore they have a name how do we 825 00:36:38,880 --> 00:36:41,318 call those 826 00:36:41,400 --> 00:36:44,680 countries no 827 00:36:44,960 --> 00:36:51,800 well the Asian tigers they grew very 828 00:36:48,318 --> 00:36:55,440 very strong for for a long time since 829 00:36:51,800 --> 00:36:57,760 the 60s or so but there you see you can 830 00:36:55,440 --> 00:37:01,679 compare if you could see you would see 831 00:36:57,760 --> 00:37:03,480 that you know that that Taiwan and the 832 00:37:01,679 --> 00:37:05,759 Democratic Republic of Congo had the 833 00:37:03,480 --> 00:37:10,079 same GDP in 834 00:37:05,760 --> 00:37:14,119 1950 okay now the Republic Democratic 835 00:37:10,079 --> 00:37:19,760 Republic of of of of Congo has less GDP 836 00:37:14,119 --> 00:37:23,880 than it had ER in 1950 it had 1700 here 837 00:37:19,760 --> 00:37:25,720 and 800 today while Taiwan Taiwan has 30 838 00:37:23,880 --> 00:37:28,480 times what it used to 839 00:37:25,719 --> 00:37:31,799 have and so today is one of the richest 840 00:37:28,480 --> 00:37:35,960 economies in the world close to 7 841 00:37:31,800 --> 00:37:40,079 $50,000 per capita while the Republic of 842 00:37:35,960 --> 00:37:44,639 Congo ER has 843 00:37:40,079 --> 00:37:47,119 700 $800 per capita so growth makes a 844 00:37:44,639 --> 00:37:49,078 big big difference okay and these are 845 00:37:47,119 --> 00:37:54,079 not that many years I mean you know this 846 00:37:49,079 --> 00:37:56,318 is just 70 years H and I can assure you 847 00:37:54,079 --> 00:37:58,079 that these people they have other 848 00:37:56,318 --> 00:38:00,159 concerns but 849 00:37:58,079 --> 00:38:01,640 their standard of living is a lot higher 850 00:38:00,159 --> 00:38:04,639 than these people and at some point they 851 00:38:01,639 --> 00:38:06,358 were the same the big difference is some 852 00:38:04,639 --> 00:38:09,639 countries that grew and some 853 00:38:06,358 --> 00:38:12,279 countries got a stuck um where is 854 00:38:09,639 --> 00:38:13,400 Argentina here I don't know somewhere 855 00:38:12,280 --> 00:38:16,599 here 856 00:38:13,400 --> 00:38:16,599 probably it's 857 00:38:18,760 --> 00:38:26,359 Argentina I don't know I cannot 858 00:38:21,880 --> 00:38:28,318 see have the chance here I can say okay 859 00:38:26,358 --> 00:38:30,159 good so growth that's make a difference 860 00:38:28,318 --> 00:38:33,119 and he has made a huge the world we see 861 00:38:30,159 --> 00:38:36,199 today and the countries we think as rich 862 00:38:33,119 --> 00:38:38,760 or poor were not the same countries that 863 00:38:36,199 --> 00:38:41,919 you thought in in those terms in 864 00:38:38,760 --> 00:38:44,160 1950 Asia is one of the most prominent 865 00:38:41,920 --> 00:38:46,440 differences they have massive growth 866 00:38:44,159 --> 00:38:48,039 through the 867 00:38:46,440 --> 00:38:51,079 60s 868 00:38:48,039 --> 00:38:53,039 um starting with Japan but then the rest 869 00:38:51,079 --> 00:38:56,280 and again were the famous the Tigers 870 00:38:53,039 --> 00:38:58,800 Hong Kong Taiwan 871 00:38:56,280 --> 00:39:02,640 Singapore uh 872 00:38:58,800 --> 00:39:08,560 and Korea South 873 00:39:02,639 --> 00:39:11,159 Korea good so let's start building some 874 00:39:08,559 --> 00:39:13,599 moles of what we have just 875 00:39:11,159 --> 00:39:16,039 seen remember when we look at the short 876 00:39:13,599 --> 00:39:18,039 run we really didn't care about the 877 00:39:16,039 --> 00:39:19,800 supply side of the economy remember it 878 00:39:18,039 --> 00:39:22,679 was all about demand they said well you 879 00:39:19,800 --> 00:39:25,560 know demand look what consumers invest 880 00:39:22,679 --> 00:39:28,000 firms and governments do with demand 881 00:39:25,559 --> 00:39:30,559 that determines output and output 882 00:39:28,000 --> 00:39:32,880 happens well it happens we didn't really 883 00:39:30,559 --> 00:39:35,078 care too much about it then when we talk 884 00:39:32,880 --> 00:39:36,920 about the medium term we say okay we're 885 00:39:35,079 --> 00:39:40,880 going to no no we have to care because 886 00:39:36,920 --> 00:39:42,440 you know to produce you need workers and 887 00:39:40,880 --> 00:39:44,640 and you know workers are not going to 888 00:39:42,440 --> 00:39:47,920 work for any wage and so we had to begin 889 00:39:44,639 --> 00:39:50,519 to talk about ER the the supply side of 890 00:39:47,920 --> 00:39:52,119 the economy but we made it very simple 891 00:39:50,519 --> 00:39:54,400 we just look at the problem of wage 892 00:39:52,119 --> 00:39:56,160 bargaining and price setting but the 893 00:39:54,400 --> 00:39:57,760 production function itself wasn't that 894 00:39:56,159 --> 00:39:59,318 interesting it was outputting equal to 895 00:39:57,760 --> 00:40:01,920 labor and I told you it's very 896 00:39:59,318 --> 00:40:04,239 unrealistic but it was convenient for 897 00:40:01,920 --> 00:40:06,440 that part of the course because Capital 898 00:40:04,239 --> 00:40:08,199 doesn't grow that fast so typical 899 00:40:06,440 --> 00:40:10,599 production function we have both capital 900 00:40:08,199 --> 00:40:12,799 and labor but at the business cycle 901 00:40:10,599 --> 00:40:14,480 frequency investment the change in 902 00:40:12,800 --> 00:40:16,039 capital can be large but the stock of 903 00:40:14,480 --> 00:40:18,039 capital doesn't move that much and so 904 00:40:16,039 --> 00:40:20,000 you can ignore it for business cycle 905 00:40:18,039 --> 00:40:22,239 type fluctuations but if we want to look 906 00:40:20,000 --> 00:40:24,400 at the long run Capital plays a huge 907 00:40:22,239 --> 00:40:27,000 role capital accumulation and so we have 908 00:40:24,400 --> 00:40:28,559 to be explicit about the role of capital 909 00:40:27,000 --> 00:40:31,239 in the the production 910 00:40:28,559 --> 00:40:32,400 function so this is going to be our now 911 00:40:31,239 --> 00:40:34,239 and now we're going to forget about 912 00:40:32,400 --> 00:40:35,800 aggregate demand we're going to say look 913 00:40:34,239 --> 00:40:37,358 we're going to focus about AGG supply 914 00:40:35,800 --> 00:40:41,640 and demand will do whatever it needs to 915 00:40:37,358 --> 00:40:46,960 do so so so we get what what the supply 916 00:40:41,639 --> 00:40:49,480 site says so output now will be will be 917 00:40:46,960 --> 00:40:51,599 a an increasing function of both capital 918 00:40:49,480 --> 00:40:54,000 and 919 00:40:51,599 --> 00:40:57,640 labor now this function will have a 920 00:40:54,000 --> 00:40:58,440 bunch of er properties which are many of 921 00:40:57,639 --> 00:41:00,879 which 922 00:40:58,440 --> 00:41:03,039 are no at a broad level they are 923 00:41:00,880 --> 00:41:04,559 empirically validated but they're also 924 00:41:03,039 --> 00:41:07,239 very convenient from the modeling point 925 00:41:04,559 --> 00:41:08,799 of view the first and most 926 00:41:07,239 --> 00:41:12,639 important 927 00:41:08,800 --> 00:41:15,280 property um is constant returns to 928 00:41:12,639 --> 00:41:19,039 scale okay we're going to use a lot of 929 00:41:15,280 --> 00:41:22,400 property so so please get that concept 930 00:41:19,039 --> 00:41:25,119 constant return to scale means simply 931 00:41:22,400 --> 00:41:28,480 that if you scale the factors of 932 00:41:25,119 --> 00:41:33,519 production you also scale the output 933 00:41:28,480 --> 00:41:36,838 okay so say if x is 1.1 that means if 934 00:41:33,519 --> 00:41:40,519 you increase capital and labor by 10% 935 00:41:36,838 --> 00:41:42,559 you get 10% more output okay so that's 936 00:41:40,519 --> 00:41:44,079 Conant return to scale if I scale all 937 00:41:42,559 --> 00:41:46,880 the factors of production by the same 938 00:41:44,079 --> 00:41:49,839 amount the same proportion then output 939 00:41:46,880 --> 00:41:51,880 Grows by the same proportion it's 940 00:41:49,838 --> 00:41:54,279 scalable that's what it mean constant 941 00:41:51,880 --> 00:41:54,280 return to 942 00:41:54,838 --> 00:42:02,599 scale very important property what comes 943 00:41:58,280 --> 00:42:02,599 next decreasing returns to 944 00:42:03,000 --> 00:42:08,519 Capital that 945 00:42:05,440 --> 00:42:11,039 is H as you increase capital for a fixed 946 00:42:08,519 --> 00:42:13,239 amount of Labor so conent scale is a 947 00:42:11,039 --> 00:42:15,679 property of scaling everything 948 00:42:13,239 --> 00:42:17,639 up the property I'm describing here is 949 00:42:15,679 --> 00:42:20,598 what happens if we increase only K what 950 00:42:17,639 --> 00:42:23,118 happens to Output if we increase only K 951 00:42:20,599 --> 00:42:27,480 but fixing 952 00:42:23,119 --> 00:42:29,039 n in other words set this to one and 953 00:42:27,480 --> 00:42:31,318 start moving this 954 00:42:29,039 --> 00:42:33,519 up you're not going to get X here you're 955 00:42:31,318 --> 00:42:36,838 going to get something different from 956 00:42:33,519 --> 00:42:39,159 X and but this tells you is that yes 957 00:42:36,838 --> 00:42:42,078 you're going to get more output but less 958 00:42:39,159 --> 00:42:45,440 and less the more Capital you 959 00:42:42,079 --> 00:42:48,079 have Okay so this says for example 960 00:42:45,440 --> 00:42:50,440 suppose you start with 100 workers and 961 00:42:48,079 --> 00:42:53,079 100 units of capital and it happens that 962 00:42:50,440 --> 00:42:57,920 this produces 100 units of 963 00:42:53,079 --> 00:42:59,640 goods if you add now 10 units of capital 964 00:42:57,920 --> 00:43:04,639 say you're going to 965 00:42:59,639 --> 00:43:06,199 get seven units of output not 10 seven 966 00:43:04,639 --> 00:43:07,920 because you didn't increase labor had I 967 00:43:06,199 --> 00:43:09,879 increased labor also by by 10 I would 968 00:43:07,920 --> 00:43:13,800 have gotten 10 of output but I 969 00:43:09,880 --> 00:43:16,519 increasing only h capital by 10 then and 970 00:43:13,800 --> 00:43:18,640 keeping output fixed then labor fixed 971 00:43:16,519 --> 00:43:21,000 then output will increase by less than 972 00:43:18,639 --> 00:43:23,199 10 but what this decrease in returns to 973 00:43:21,000 --> 00:43:26,639 Capital says is that now if you increase 974 00:43:23,199 --> 00:43:27,960 again from 110 to 120 units of capital 975 00:43:26,639 --> 00:43:30,279 you're going to get get less than seven 976 00:43:27,960 --> 00:43:32,480 units of output more you're going to get 977 00:43:30,280 --> 00:43:34,720 five and if you increase a again from 978 00:43:32,480 --> 00:43:37,199 120 to 130 you're going to get less than 979 00:43:34,719 --> 00:43:39,199 five you're going to get three and so on 980 00:43:37,199 --> 00:43:41,960 so forth that's decreasing returns to 981 00:43:39,199 --> 00:43:45,598 scale and and decreasing returns to 982 00:43:41,960 --> 00:43:47,838 Capital and the reason for that is is 983 00:43:45,599 --> 00:43:49,280 economically is that more and more 984 00:43:47,838 --> 00:43:51,440 capital is working with a fixed number 985 00:43:49,280 --> 00:43:52,400 of workers so labor becomes very scarce 986 00:43:51,440 --> 00:43:55,440 for 987 00:43:52,400 --> 00:43:57,720 capital okay and that's the reason so so 988 00:43:55,440 --> 00:43:58,838 you have very little 989 00:43:57,719 --> 00:44:00,439 the other these are factors of 990 00:43:58,838 --> 00:44:02,799 production which are complementary they 991 00:44:00,440 --> 00:44:05,760 need each other labor and capital if you 992 00:44:02,800 --> 00:44:07,760 fix one and it start increasing only one 993 00:44:05,760 --> 00:44:09,720 then it's harder and harder for each 994 00:44:07,760 --> 00:44:11,839 extra new unit of this one to work with 995 00:44:09,719 --> 00:44:13,480 sort of fewer and fewer of the other 996 00:44:11,838 --> 00:44:16,000 factor of production so the same 997 00:44:13,480 --> 00:44:18,639 principle applies to labor if you fix 998 00:44:16,000 --> 00:44:21,480 capital and you only increase labor then 999 00:44:18,639 --> 00:44:22,920 initially you get a big jumping output 1000 00:44:21,480 --> 00:44:26,318 but it's going to be smaller and smaller 1001 00:44:22,920 --> 00:44:29,039 and smaller the more you keep adding a 1002 00:44:26,318 --> 00:44:29,039 um 1003 00:44:29,119 --> 00:44:36,960 labor okay so in pi so let me One X that 1004 00:44:34,079 --> 00:44:40,880 we're going to use 1005 00:44:36,960 --> 00:44:46,318 throughout is we want to make x one of 1006 00:44:40,880 --> 00:44:46,318 our favorite X will be 1 / 1007 00:44:46,400 --> 00:44:52,760 n you see what I'm trying to do when we 1008 00:44:49,039 --> 00:44:56,239 set x equal to 1 / n so that x equal to 1009 00:44:52,760 --> 00:44:58,440 1 / n what I get here is output per 1010 00:44:56,239 --> 00:45:00,239 person 1011 00:44:58,440 --> 00:45:02,519 no that's what I 1012 00:45:00,239 --> 00:45:08,039 get y Over 1013 00:45:02,519 --> 00:45:09,920 N so if I set xal to 1/ n i can using 1014 00:45:08,039 --> 00:45:11,079 con to scale I know that this is equal 1015 00:45:09,920 --> 00:45:16,159 to 1016 00:45:11,079 --> 00:45:18,839 y/n k/ n n/ n so that is one so this guy 1017 00:45:16,159 --> 00:45:22,239 doesn't move and I have now 1018 00:45:18,838 --> 00:45:24,679 that a output per person is increasing 1019 00:45:22,239 --> 00:45:26,039 in capital per worker worker and 1020 00:45:24,679 --> 00:45:28,719 population this part of the course are 1021 00:45:26,039 --> 00:45:31,639 the same for get an EMP employment and 1022 00:45:28,719 --> 00:45:34,358 is population is employment if labor 1023 00:45:31,639 --> 00:45:38,440 force is everything I'm not this is not 1024 00:45:34,358 --> 00:45:38,440 a place to worry about unemployment 1025 00:45:41,800 --> 00:45:47,640 okay okay so remember that all the plots 1026 00:45:45,079 --> 00:45:50,039 I show you the different Figures were 1027 00:45:47,639 --> 00:45:52,078 about this variable how it changed over 1028 00:45:50,039 --> 00:45:54,679 time how was different across different 1029 00:45:52,079 --> 00:45:57,800 countries how grew at a different rate 1030 00:45:54,679 --> 00:46:00,879 in in different countries but from this 1031 00:45:57,800 --> 00:46:01,839 very simple model you see that in order 1032 00:46:00,880 --> 00:46:05,039 to 1033 00:46:01,838 --> 00:46:07,119 explain the change in this or growth in 1034 00:46:05,039 --> 00:46:09,719 why over and why one country grows more 1035 00:46:07,119 --> 00:46:12,960 than the other you have with the simple 1036 00:46:09,719 --> 00:46:12,959 model only two 1037 00:46:13,280 --> 00:46:20,720 options so if I tell you country a grew 1038 00:46:17,559 --> 00:46:23,280 more over this period than grew more per 1039 00:46:20,719 --> 00:46:28,358 per person than this other 1040 00:46:23,280 --> 00:46:29,920 country er um over this period of time 1041 00:46:28,358 --> 00:46:32,239 there are only two options here the 1042 00:46:29,920 --> 00:46:34,400 first one is that in that country there 1043 00:46:32,239 --> 00:46:37,879 was more capital accumulation per worker 1044 00:46:34,400 --> 00:46:39,838 so K Over N went up no if K Over N goes 1045 00:46:37,880 --> 00:46:42,960 up more in one country than the other 1046 00:46:39,838 --> 00:46:45,679 one y Over N will go up more in that 1047 00:46:42,960 --> 00:46:49,559 country than the other one and the other 1048 00:46:45,679 --> 00:46:51,358 option is that the this H function 1049 00:46:49,559 --> 00:46:56,280 itself shifted 1050 00:46:51,358 --> 00:46:58,719 up so for any given amount of K Over N 1051 00:46:56,280 --> 00:47:00,359 now you could produ more y over n and 1052 00:46:58,719 --> 00:47:04,078 that's what we call technological 1053 00:47:00,358 --> 00:47:07,239 progress that's a second thing so so if 1054 00:47:04,079 --> 00:47:09,760 if if the difference in in in in growth 1055 00:47:07,239 --> 00:47:12,358 of output per 1056 00:47:09,760 --> 00:47:13,880 person is due to an increasing K Over 1057 00:47:12,358 --> 00:47:16,358 end well we call that a capill 1058 00:47:13,880 --> 00:47:18,880 accumulation mechanism if it is because 1059 00:47:16,358 --> 00:47:20,759 the function f shifts up that's 1060 00:47:18,880 --> 00:47:22,680 technological progress and what we're 1061 00:47:20,760 --> 00:47:24,359 going to do is in the next lecture we're 1062 00:47:22,679 --> 00:47:28,440 going to talk about this channel the 1063 00:47:24,358 --> 00:47:30,880 capital accumulation Channel and in the 1064 00:47:28,440 --> 00:47:32,960 lecture after the spring break we're 1065 00:47:30,880 --> 00:47:36,400 going to talk about shift in the 1066 00:47:32,960 --> 00:47:38,318 function f so in in in in 1067 00:47:36,400 --> 00:47:40,760 figures 1068 00:47:38,318 --> 00:47:43,199 so fixing the technology that this is 1069 00:47:40,760 --> 00:47:45,480 the function f is fixed and you just 1070 00:47:43,199 --> 00:47:48,279 move K Over N this is the picture you 1071 00:47:45,480 --> 00:47:51,000 have now that's a produ this I'm 1072 00:47:48,280 --> 00:47:55,079 plotting this function here as a 1073 00:47:51,000 --> 00:47:57,559 function of k/ n for a fixed function f 1074 00:47:55,079 --> 00:48:00,318 and that's what you get so output per I 1075 00:47:57,559 --> 00:48:02,160 have here Capital per worker and output 1076 00:48:00,318 --> 00:48:05,400 per per 1077 00:48:02,159 --> 00:48:06,838 worker and you see that obviously it's 1078 00:48:05,400 --> 00:48:08,240 in an increasing function the more 1079 00:48:06,838 --> 00:48:10,199 Capital per worker you have the more 1080 00:48:08,239 --> 00:48:13,799 output per worker you'll 1081 00:48:10,199 --> 00:48:13,799 produce but it's also 1082 00:48:13,920 --> 00:48:17,318 concave why is it 1083 00:48:19,559 --> 00:48:25,559 concave that's decrease in returns to 1084 00:48:21,760 --> 00:48:28,000 Capital is look for any when you have 1085 00:48:25,559 --> 00:48:30,040 very little Capital per work 1086 00:48:28,000 --> 00:48:31,519 a change in capital per worker gives 1087 00:48:30,039 --> 00:48:33,800 gives you a big jumping output per 1088 00:48:31,519 --> 00:48:35,239 worker because you know there was sort 1089 00:48:33,800 --> 00:48:36,760 of very little Capital that was the 1090 00:48:35,239 --> 00:48:39,318 problem of that 1091 00:48:36,760 --> 00:48:42,800 economy when the economy has more and 1092 00:48:39,318 --> 00:48:44,880 more Capital the same change in capital 1093 00:48:42,800 --> 00:48:47,519 leads to a much smaller change in output 1094 00:48:44,880 --> 00:48:49,599 here at this level when when Capital per 1095 00:48:47,519 --> 00:48:53,798 worker was very low the economy was very 1096 00:48:49,599 --> 00:48:56,798 poor then this change LED to this change 1097 00:48:53,798 --> 00:48:59,480 in output per capita at this level of 1098 00:48:56,798 --> 00:49:01,358 wealth if you get as capital economies 1099 00:48:59,480 --> 00:49:04,400 with higher Capital are richer Capital 1100 00:49:01,358 --> 00:49:06,199 per worker the same change this change 1101 00:49:04,400 --> 00:49:08,079 is of the same size as that leads to a 1102 00:49:06,199 --> 00:49:10,558 much smaller change in 1103 00:49:08,079 --> 00:49:13,559 output okay and that's a result of 1104 00:49:10,559 --> 00:49:15,640 decreasing returns to 1105 00:49:13,559 --> 00:49:16,720 Capital and that's the other option 1106 00:49:15,639 --> 00:49:20,078 again that's what we're going to talk 1107 00:49:16,719 --> 00:49:21,519 about in the next lecture this this one 1108 00:49:20,079 --> 00:49:24,000 and two lectures from now we're going to 1109 00:49:21,519 --> 00:49:25,519 talk about growth that comes from shift 1110 00:49:24,000 --> 00:49:27,440 in the production function this 1111 00:49:25,519 --> 00:49:32,679 technological progress 1112 00:49:27,440 --> 00:49:32,679 okay very good see you on Wednesday