Seasonal variation in infant mortality in India.

Investigating seasonal variation in health helps us understand interactions between population, environment, and disease. Using information on birth month and year, survival status within the first year of life, and age at death (if applicable) of more than 330,000 children observed in four rounds of India's Demographic and Health Surveys, I estimate period mortality rates between birth and age one (₁m₀) by calendar month. Relative to spring months, infant mortality is higher in the summer, monsoon, and winter months. If spring mortality conditions had been prevalent throughout the year, mortality below age one would have been lower by 11.4 deaths per 1,000 in the early 1990s and 3.7 deaths per 1,000 in the mid-2010s. Seasonal variation in infant mortality has declined overall but remains higher among disadvantaged children. The results highlight the multiple environmental health threats that Indian infants face and the short time of year when these threats are less salient.