 I'm Salvatore Bobonis and in today's video I'm going to show how to use the US Census Bureau's International Database to produce population pyramids for different countries. To get there, just Google Census Bureau IDB for International Database and you'll easily get to this page, click through to the database itself, and then on the report you'd like choose Population Pyramid Graph. Now the Census Bureau produces animated population pyramids if you choose several years, and I'm going to start with years at 10 year increments starting with 1980, and if I hold down the control key I can highlight multiple years. The Census Bureau actually has data going way back to I think 1960, but it also gives projections out through 2050. And while you might think that projections to 2050 are pretty dicey, in fact population tends to move in very slow arcs. I mean consider that everyone is going to give birth in the next 20 years is pretty much already been born, so you can pretty well predict what the population is that's going to be given birth and fertility rates move in predictable ways. It's really pretty sound to do population projections out for 30 or 40 years. I'm going to start by looking at the projections for China, I click submit. I'm starting with China because China is maybe the most dramatic case of demographic change that we have in recent years. You'll see the data for China only started in 1990 after all, and here you can see the population pyramid for 1990, 2000, and if you were to scroll along all the way up to 2050. It's called a Population Pyramid because it's arranged in such a way that on the horizontal axis are millions of people, on the left side are males and the right side are females. So this first line would indicate that between zero and four years old, there are something like 68 million Chinese boys and 60 something million Chinese girls. And it's called a pyramid because obviously as you get older, older and older and older, there are fewer and fewer people because people tend to die with age. There are no more people being made at older ages, they're always being dying off at older ages. So we end up with a pyramid shape for most populations. If we animate China's population, we can do that by just clicking this play button. You'll see the effects of China's one child policy. China started with a one child policy in the 1970s, made it even more aggressive in the 80s and 90s, and as a result, China's new births have declined generation after generation. Here you can see the large bulge of people who were born before the one child policies. People were born in the 1950s, 60s and early 70s, aging their way through the ranks until by 2050, China will have a very old population indeed. Now we can contrast China's population pyramid with other countries. So for example, I'll take a look at Australia. Australia has a very healthy population pyramid. There are no massive government policies that have worked the structure of the population, but instead when you look at Australia, you can see simply huge population growth. So while Australia's population structure is pretty stable, it's just growing very rapidly. What's more, you can see that consistently over a 60-year period, there are more Australians in the adult middle age ranges than there are young Australians. Now normally that would be impossible because as I said, people are born and then they die, but in Australia, levels of immigration are so enormous and immigrants obviously are not children. Immigrants have to be adults or at least adults with children, but you typically don't have unaccompanied four-year-olds immigrating to countries. So as a result, Australia has this big bulge of middle age populations. And this is actually very healthy for Australia's economy because these are people of high productivity. Whereas in China, the people of high productivity are aging through the system so that by 2050 they'll be in their low productivity elder years. In Australia, because of massive immigration, there's a continuous stream of Australians of high productivity. That said, the population gets larger and larger and larger and larger exponentially, so Australia won't be able to keep this up forever. The question is how long will it choose to? Okay, so in different ways, China and Australia both have quite pathological population structures. If we look at a third country, I'm going to go here to Nigeria, which has one of the highest birth rates in the world. And let's animate Nigeria's period. These are all 1990 through 2050. You'll see that Nigeria's population is just getting bigger and bigger and bigger via more and more and more births. So every year there are more children being born and that large cohort then moves up a year and another large cohort is born after it. So Australia or Nigeria here is in a position of exponential population growth due to a very high fertility rate. And in fact Nigeria is likely to overtake the United States in population very soon and may even overtake China by the end of the century. That's right. By the year 2100, it's likely, not certain, but likely that there will be more people in Nigeria than there are in China. So get your head around that. Alright, let's look now at Japan. Japan has China's problem in spades. Japan has a very severely aging population due to decades of low birth rates and low fertility. And if we look at Japan, you can see that Japan like China only more severely has an aging population of smaller and smaller and smaller birth cohorts as this bulge of people born in the 1960s passes through the population and is going to be quite old indeed by mid century. Alright, well, after seeing all these pathological population periods, it might be interesting to look at a stable one, a country that has a modest amount of in migration that has a birth rate that's or fertility rate that's close to replacement is right around two children per woman. And that country is France. So if we look at France's population pyramid, you'll see instead, you know, a pretty stable population. I mean a population that is roughly the same generation after generation with, you know, age population aging due to improved health care over time, but not a lot of massive change like you see in these other countries we have looked at. Alright, that's about it. I'll just quickly note that you can get all sorts of population data from the Census Bureau and that goes back to 1950 actually and forward to 2050. And you can get it for pretty much every country in the world. There are other sources of data for other countries, but many for many countries is very difficult to get good estimates. And in fact, if you would like to know, you know, population by age group, you know, five year age group for, you know, a small country like Estonia, the Census Bureau will give you a pretty good estimate. The only other place you can get estimates like this are the United Nations population division, which has similar estimates based on slightly different methodology, but you'll get very similar numbers. Or if you go to each country's individual data bureau, you might be able to get data, or you might not. Most of us as professionals use the Census Bureau and the UN population division as our data sources. Hope you enjoyed the lecture and thanks for watching.