The distributional impact of SNAP on dietary quality

The Supplemental Nutrition Assistance Program (SNAP) is the nation's largest domestic food and nutrition assistance program for low-income Americans. Recent studies that examined the effect of SNAP on dietary quality focus on the average effects. Using the USDA's 2012 National Household Food Acquisition and Purchase Survey (FoodAPS) and an unconditional quantile estimator, we examine the distributional impacts of SNAP on dietary quality as measured by Healthy Eating Index-2010 (HEI-2010). To identify the differential impacts of SNAP across the distribution of dietary quality, we exploit exogenous variation in state's maximum weekly unemployment insurance benefits and state outreach spending per capita as instrumental variables. We find that SNAP has no significant impact on households’ dietary quality on average. However, for households with initially low-to-intermediate dietary quality, SNAP participation reduces their HEI scores by over 17% or more than 7 points out of a total score of 100. The negative impacts of SNAP on these HEI quantiles are mainly driven by an increased acquisition of empty calories.