Posted on August 6, 2009

Fertility Rates Climb Back Up in the Most Developed Countries

Ed Yong, ScienceBlogs, August 5, 2009


But Mikko Myrskyla from the University of Pennsylvania thinks differently. He has found that the most developed countries have actually reversed their falling fertility rates, possibly by improving gender equality and making it easier for women to raise families while enjoying successful careers. The result is a graph that looks like a reverse tick, with a small upturn in fertility rate that only becomes evident when looking at data from the dawn of the 21st century. At the most advanced stages of development, it seems that babies make a comeback.


{snip} Myrskyla’s data {snip} compared the fertility rates of 107 countries in 1975 with their scores on the Human Development Index–a measure of the level of development that takes into account life expectancy, literacy, education and standards of living. He did the same for 140 countries in 2005.

In both years, Myrskyla found that the greater a country’s HDI score, the lower its fertility rates, but only up to a point. At scores of 0.9 or over (and the range goes from 0 to 1), the trend reverses so that women from the most developed countries have , on average, more babies. This trend only became obvious by looking at the more recent set of data for in 1975, no country had reached the stage of development where fertility rates pick up again. Then, the top score was 0.887, while Australia is currently in the lead with 0.966.

The upturn is small but significant. If a country’s HDI score is between 0.9 and 0.92 (as is the case for South Korea or Germany), the average fertility rate is low enough at 1.24 for the population to halve in size every 40-45 years. However, countries with the highest scores (including Australia and Scandinavia) have an average fertility rate of 1.89–not quite the replacement level, but close enough that small levels of migration can sustain the same population.

Myrskyla saw the same trend when he focused on individual countries over the last 30 years. There were a few exceptions but in general, as countries became more developed, babies came back into fashion. In the US, falling fertility reversed in 1976 at an HDI score of 0.881. In Norway, it happened in 1983, at a score of 0.892. Myrskyla reckons that the critical point is around 0.86–beyond this stage of development, an extra 0.25 points on the HDI score translates to roughly one extra baby for every woman.

The big question, of course, is what’s behind the reversal? It certainly seems to apply to a diverse set of cultures and the exceptions (including Japan, Canada and South Korea) are hardly that similar. Myrskyla thinks that high HDI scores reflect societal changes that make it easier for women to choose to have children. As equality becomes more strongly felt, women get a better education, earn more jobs and command higher salaries. That makes it easier for them to cope with the financial drain of children, and for them to successfully take time out of the rat race and re-enter later on.

It’s possible that rich east Asian countries like Japan and South Korea have failed to buck the fertility trend because they have failed to address the challenges of gender equality and work-family balance that other countries have begun to tackle. Still, that doesn’t explain Canada. In a related editorial, Shripad Tuljapurkar suggests that the HDI itself may be to blame. It doesn’t tell us anything about whether development affects men and women equally, and in that respect, the Gender Development Index (GDI) maybe a more useful measure.

All in all, Myrskyla’s results paint a slightly rosier outlook for much of the world. As he writes, “As long as the most developed countries focus on increasing the well-being of their citizens, and adequate institutions are in place, the analyses in this paper suggest that increases in development are likely to reverse fertility declines–even if we cannot expect fertility to rise again above replacement levels.” {snip}