National population trends depend on a number of factors, including such things as fertility rates, death rates, immigration, and emigration.  At this point, though, I’m only going to look at general population trends for a few countries, without looking into particular influences or causes: today’s age breakouts compared with their projections over the next couple of generations, along with current net immigration rates, for Brazil, the People’s Republic of China, Russia, Germany, France, Great Britain, and the United States.  This list is selected purely for an initial, superficial look in the mirror and at some of our major economic competitors (with the deliberate exclusion of the EU as a whole, since it remains sufficiently fragmented among its constituent nations from a political and economic perspective that some of the individual nations are more important to me than the continent).  The UN’s report World Population Ageing: 1950-2050 is my source for the population data; I massaged data from the CIA’s The World Factbook 2011 snapshot for the immigration numbers.

In Brazil, nearly 63.5% of the population was in the age band 15-59, while those 60 and older comprised under 8%.  By 2025 (one generation after those 2000 figures), these are expected to have shifted to 62.5% and a shade over 15%, while in just one more generation, by 2050, the numbers are expected to have shifted to 56.5% and a bit over 23.5%, respectively.  The support ratio, the number of people in the actual labor force (15-64 years old, nominally available to contribute to the support of the elderly) per person 65 or older, reflects this shift and emphasizes the problems confronting an aging population: the support ratio is expected to shift, over those same two generations, from 12.9 to 1, to 6.6 to 1, to 3.5 to 1—or the number of workers supporting that older population is expected to fall by nearly 75%.  The fertility rate (loosely, the number of children per woman during her child-bearing years) is expected to remain just at the replacement rate of 2.1.  Brazil has a net emigration rate close to zero; movement into/out of the country plays almost no role in Brazil’s population and its future economic impacts.

Here are numbers for the People’s Republic of China:

The size of the work force available to support that aging population is expected to fall, in relative terms, by two-thirds.  China has a net emigration rate roughly 450,000 persons per year.  This, coupled with that below replacement fertility rate will continue to present the nation with an economic problem in efforts to support that relatively expanding aging population.  Moreover, this shortfall can only be exacerbated by the one-child policy and its associated gender bias in the coming generations.

In Russia, the numbers stack up like this:

There are a couple of points here.  Russia starts this period with a low number of workers per old person.  Indeed, they haven’t had a support ratio above 7.7 since 1975.  Also, the fertility rate is at disastrous levels—this is a population implosion in progress.   The trend is in the right direction, but in our two generations it still doesn’t reach the replacement level—and that ratio is from a rapidly shrinking population base.  The situation is very dicey for Russia.  Russia gains, due to immigration, roughly 40,000 persons per year; however, despite this, the country experienced an annual population decline of 650,000 in 2011, and this will continue until the combination of immigration and fertility rate can reverse the trend.

The German numbers are these:

The situation looks as bad for Germany as it does for Russia; however, there is a critical difference: the German economy is a much more productive economy, owing to its relatively free market operation.  Germany also accepts a large number of guest workers (although not all become immigrants); these are not reflected in the above population figures.  Separate from the guest worker program, Germany experienced a slight net immigration, yet it still lost, as of that 2011 snapshot, roughly 170,000 persons.

The French numbers are these:

The projected French support ratio is in better shape than the German one, and this seems related to the somewhat more stable age break out between the two population bands.  The fertility rate doesn’t reach the replacement rate, but France, like Germany, accepts a large number of guest workers.  So far, the relatively free market tenets of the French economy makes it, like Germany’s, more productive than most; this mitigates (but does not eliminate) the economic results of the unfavorable population trends.  France had a net immigration of some 100,000 persons in 2011, and its population grew by 325,000 that year.  The net influx of immigration clearly is helping stabilize/grow the French population.

The numbers for Great Britain are these:

The British fertility rate is too low, but its trend is the most favorable of the three EU countries presented.  Like France and Germany, the British also accept a large number of guest workers.  The British economy, especially after Thatcher’s earlier reforms and Cameron’s present efforts, is  a relatively free market one, and so highly productive.  This, as with Germany and France, helps mitigate the economic impact of its unfavorable population trends.  Great Britain had a net immigration of some 163,000 persons in 2011, and its population grew by nearly 350,000.  As with France, immigration is helping the stabilize/grow the British population.  In both countries, net immigration may be going a long way toward slowing, and mitigating the effects of, the projected decrease in support ratio over the next two generations.

The numbers for the United States look like this:

The Baby Boomer generation is much of the spike in the first generation after the 2000 data; after that, the rates begin to stabilize (although we’d need to see more generations of data before stabilization can seriously be claimed), and the fertility rate reaches near replacement by 2050.  The US’ economy is the freest of the nations surveyed; this relatively higher productivity goes a long way toward mitigating the economic effects to the population age band trend.  The US experienced a net immigration of 1.3 million and a population growth of over 3 million in 2011.  This immigration rate also will be critical in overcoming the support ratio decrease over the next couple of generations, even though that ratio may begin to stabilize after that.

Even in a centrally managed economy, new workers are needed to produce the economic output required to support those too old to work—the work force must be replenished at least as fast through births and immigration as it is depleted through aging and death.  It’s important to note at this point that guest workers may not be a long-term answer.  All three of the EU countries above are starting to have—or think they’re starting to have—problems with their guest worker populations.  Moreover, the long-term work force and support ratio solutions—the overall population and economic output trends—depend on a net influx of permanent members of the population: birth rates and immigration rates.

With our more productive and flexible (relatively) free market economy, we still need immigration just to maintain our work force, much less support our own aging population, even with our projected replacement rate fertility level.  This puts a premium on getting control over our borders while making it easy for people to enter our country legally, and to stay legally once have arrived.