Regular ArticleThe persistent effects of in utero nutrition shocks over the life cycle: Evidence from Ramadan fasting

- Life cycle impacts of prenatal exposure to Ramadan fasting are considerable.
- There are large adverse effects on labor supply and cognitive skills for Muslims.
- Novel data on religiosity suggests that compliance to Ramadan fasting is a factor.
- Results are robust to sibling fixed effects and higher among religious Muslims.

More than a billion Muslims living today were potentially exposed to their mother's fasting in utero. This paper uses the Indonesian Family Life Survey to study the persistent effects of in utero exposure to Ramadan over the life cycle. The exposed children perform more child labor, score 7.4% lower on cognitive tests and 8.4% lower on math test scores. As adults, the exposed children work 4.7% fewer hours per week and are more likely to be self-employed. Estimates are robust to the inclusion of family fixed effects, particularly for hours worked and test scores. Moreover, results are strongest for religious Muslim families, while insignificant for non-Muslims. Back of the envelope calculations reveal an implied fasting rate of 68%-82% among pregnant Muslim women.