Trends in physical stature across socioeconomic groups of Chilean boys, 1880-1997

- Chilean boys aged 5-18 born between 1880 and 1997 grew 1.1 cm per decade, on average.
- A large socioeconomic stature difference of 9-11 cm is observed up to the late 1940s.
- Since then, the socioeconomic stature gap decreased rapidly to about 5 cm in 1990s.
- Height convergence by SES was driven by increases in height of lower & middle SES boys.
- We argue this was associated with a steady expansion of social policies since the 1940s.

This paper studies the trends in height-by-age across socioeconomic groups of Chilean boys aged 5-18 born between 1880 and 1997, by performing a meta-analysis of 38 studies reporting height-by-age published since 1898. We estimate the trends using quantile regressions and by analyzing detailed height data from five selected studies. Both methods yield an average decennial increase in height of 1-1.1 cm, and 0.9 and 1.2-1.3 cm for boys of upper and lower socioeconomic status (SES), respectively. SES differences in heights of 9-11 cm are observed up to the late 1940s. However, boys born after the 1930s exhibit substantial convergence in height between socioeconomic groups, driven by an increase in height of middle and lower SES boys of 1.5 and 1.4-2 cm per decade, respectively. As a result, SES differences in height decreased to 5 cm in 1990s. Since these changes occurred in a context of moderate economic growth and persistent income inequality, we argue that our findings are associated with the emergence and expansion of social policies in Chile since the 1940s, which delivered steady improvements in health, nutrition and living conditions.