Effects of posted point-of-sale warnings on alcohol consumption during pregnancy and on birth outcomes.

In 23 states and Washington D.C., alcohol retailers are required by law to post alcohol warning signs (AWS) that warn against the risks of drinking during pregnancy. Using the variation in the adoption of these laws across states and within states over time, I find a statistically significant reduction in prenatal alcohol use associated with AWS. I then use this plausibly exogenous change in drinking behavior to establish a causal link between prenatal alcohol exposure and birth outcomes. I find that AWS laws are associated with decreases in the odds of very low birth weight and very pre-term birth.