Political gender inequality and infant mortality in the United States, 1990-2012

•Finds strong link between political gender inequality and IMRs in the U.S.•Projects the population level costs of women's underrepresentation in 2012.•Suggests women's political empowerment is important for U.S. population health.

Although gender inequality has been recognized as a crucial factor influencing population health in the developing world, research has not yet thoroughly documented the role it may play in shaping U.S. infant mortality rates (IMRs). This study uses administrative data with fixed-effects and random-effects models to (1) investigate the relationship between political gender inequality in state legislatures and state infant mortality rates in the United States from 1990 to 2012, and (2) project the population level costs associated with women's underrepresentation in 2012. Results indicate that higher percentages of women in state legislatures are associated with reduced IMRs, both between states and within-states over time. According to model predictions, if women were at parity with men in state legislatures, the expected number of infant deaths in the U.S. in 2012 would have been lower by approximately 14.6% (3,478 infant deaths). These findings underscore the importance of women's political representation for population health.