When looking at programs that mostly target infant mortality, I’ve mostly thought of them as “population-increasing” programs. I’ve sympathized with donors who say that bigger populations might be the last thing poor villages need, and I’ve also assumed that “strict utilitarians” are likely to value such programs more than I do. It’s interesting to see the Report of the Commission on Macroeconomics and Health try to turn this issue on its head:
…high mortality rates of children tend to provoke high fertility rates among poor couples. In general, the high fertility more than compensates for the high mortality … In one numerical illustration, households whose children have a 75-percent survival rate choose to have six children, of whom an average of 4.5 survive. The households whose children have a 95-percent survival rate have two children, of whom an average of 1.9 survive … This pattern helps us to understand the surprising fact that countries with high infant mortality rates have the fastest growing populations in the world…
The report includes charts (see Pgs 35-38) showing a pretty strong association between low infant mortality and low population growth across the world’s nations.
This statistical association doesn’t necessarily mean the above logic is correct; it could be that something else, such as economic prosperity or education, is associated with both low infant mortality and low population growth, and that simply lowering infant mortality wouldn’t reduce fertility.
Not being aware of any studies on this specific relationship, I looked a little further using Gapminder. Rather than looking across the world’s countries (as the Report does), I looked specifically at countries within sub-Saharan Africa over time, which seems more relevant to the hypothesis that lowering infant mortality in high-mortality, high-fertility countries (such as those in sub-Saharan Africa) is associated with lowering fertility.
Since 1950, these countries have seen noticeable declines in both infant mortality and fertility (children per woman). However, the trends don’t sync up. In particular, since 1990, infant mortality has largely remained flat while fertility has continued to decline. (Note that literacy has improved over this time period as well.)
I’m hesitant to go as far as the report in calling infant mortality a primary, or the primary, driver of lower fertility. Still, it is clear at least that reducing infant mortality need not result in population growth. I don’t know of any more thorough studies on the link, and would be interested in any references.