Tuesday, January 10, 2006

Don't know much about demography


Regarding the low birthrates in various countries, could you please explain the calculation behind your observation that the population of Spain will decrease by 50% over the next generation.
Ernest WoodClinton, Mississippi

MARK REPLIES: I meant what I said – that Spain’s population halves with every generation. That’s to say, Generation A has 1.1 children per couple. That means, as a demographic cohort, Generation B will be half the size of Generation A: two million grown-ups will have one million children. If Generation B reproduces at the same rate, Generation C will be half the size of Generation B and only a quarter of Generation A: that’s to say, two million grandparents will have half a million grandchildren. By the time you get to Generation D, you’re looking at some pretty irreversible math. More to the point, how many of those half a million are going to stick around if they have to bear the economic load of supporting those two million seniors. A significant chunk of Generation B and C will act in their economic interests and skip elsewhere.


Post a Comment

<< Home