Robert Waldmann: Hoynes, Schanzenbach, and Almond with Convincing Evidence That Food Stamps--SNAP--Really Do Work: Monday Focus
Hilary W. Hoynes, Diane Whitmore Schanzenbach, Douglas Almond made a genuinely important contribution in “Long Run Impacts of Childhood Access to the Safety Net”. They took advantage of a quasi-natural experiment to estimate the long-run effects of access to Food Stamps (SNAP) in utero and in early childhood. From 1964, when counties could first provide food stamps, until 1973, participation in the program increased pretty much linearly: in 1968 food stamps were provided in roughly half of US counties. Thus they can estimate the effect of Food Stamps by comparing the experience of people whose parents did not have high school diplomas born at the same time in counties with and without Food Stamps, they can estimate the effect of food stamps.
Here is the abstract:
A growing economics literature establishes a causal link between in utero shocks and health and human capital in adulthood. Most studies rely on extreme negative shocks, such as famine and pandemics. We are the first to examine the impact of a positive and policy-driven change in economic resources available in utero and during childhood.... We focus on the introduction of... the Food Stamp Program... rolled out across counties in the U.S. between 1961 and 1975. We use the Panel Study of Income Dynamics to assemble unique data linking family background and county of residence in early childhood to adult health and economic outcomes. The identification comes from variation across counties and over birth cohorts in exposure to the food stamp program.
Our findings indicate that the food stamp program has effects decades after initial exposure. Specifically, access to food stamps in childhood leads to a significant reduction in the incidence of “metabolic syndrome” (obesity, high blood pressure, and diabetes) and, for women, an increase in economic self-sufficiency. Overall, our results suggest substantial internal and external benefits of the safety net that have not previously been quantified.
Food stamps are thus a demonstrably effective way to fight the culture of poverty. The sincere belief of Paul Ryan’s favorite anti-poverty worker Bishop Shirley Holloway that “You don’t dream when you’ve got food stamps” has been proven false. But it never made much sense, since SNAP is available to the working poor. Conservalogic says that benefits to the working poor sap their energy in a mysterious way. If this were true, it would affect the Hoynes et al. results.
Also note: Food Stamps have a significant long-term effect on obesity. Obesity was signficantly reduced by pre- and neo-natal access to food stamps (well, access to the nutrients--I mean the fetuses couldn’t actually grab the food stamps, and the babies would have tried to eat the stamps not buy food with them). This causes me to doubt the judgment of Charles Lane who challenged the claim that food insecurity is a major problem in the USA and asked:
Look at the people on the street today: Based on that, would you say that America has a hunger problem or an obesity problem?
As anyone who looked at the same street would guess, food insecurity causes later obesity. The Hoynes et al. paper rejects the null that it does not at the 5% level.
There is a small chance that the statistical analysis of Hoynes, Whitmore, and Almond will have some effect on the current debate in Congress over how much to cut SNAP. Convincing evidence that the indirect effects of SNAP add to the direct benefits of reducing hunger should be influential. I don’t really expect evidence to have much effect on Congress, but do spread the word. It is important.