Saturday, July 1, 2017

Population growth responds to economic conditions


It is often argued that the economy's performance depends upon population growth. No doubt, but economic forces typically work in both directions and, if that is true, then it is also true that population growth depends upon the economy's performance.

Googling us population historical data excel turns up World Population Data (3) as the first result. Their population.xls file contains a worksheet named US Population Data - Filled in which will serve my purpose. The initial notes say

Before 1960, 10 year census data was filled in assuming constant annual growth during that decade. From 1960, Current Population Survey estimates are used.

So the data for the time of the Great Depression time is not perfect, but I probably won't find anything better. They provide this graph:

Graph #1: From the Population.XLS file
You can easily see a slowdown of population growth from 1930 to 1940. That's gotta be a result of the Great Depression. Malthusian. Here is a plot of the growth rate:

Graph #2: Population Growth Rates, based on the data from Graph #1
You can see the low of the 1930s, a low which supports the view that population growth responds to economic conditions. And you can see the high of the 1950s, likely in part a result of the improved economic conditions of that time.


Diane J. Macunovich writes:

Many factors can influence a couple’s decision to have a child, but a large body of work suggests that economic factors—especially women’s wages and young adults’ relative income—have played a major role in U.S. fertility trends. “Relative income” refers to a person’s earning potential relative to his or her desired standard of living.

If your "desired standard of living" is high, you might be inclined to put off having children and instead devote more time to your career. That would tend to push the economic trend and the population trend in opposite directions. No doubt it's a factor.

I think more in terms of our expected standard of living -- low during the Great Depression, high after a victorious end of WWII. These would tend to push the economic trend and the population trend in the same direction.

Both tendencies exist, no doubt. But it seems to me that major events (like the Great Depression and the end of World War Two) would give a general push in one direction or another. People do always have their own goals and their own desires, but for a large number of people these would tend to average out. So the general trend of population growth in an economy like ours must be subject to the push of major economic events.

1 comment:

The Arthurian said...

Adam Smith: "The most decisive mark of the prosperity of any country is the increase of the number of its inhabitants."