No abstract

Naturally-occurring Yellow Dust outbreaks, which are produced by winds flowing to Korea from China and Mongolia, create air pollution. Although there is a seasonal pattern of this phenomenon, there exists substantial variation in its timing, strength, and location from year to year. To warn residents about air pollution in general, and about these dust storms in particular, Korean authorities issue different types of public alerts. Using birth certificate data on more than 1.5 million babies born between 2003 and 2011, we investigate the impact of air pollution, and the avoidance behavior triggered by pollution alerts on various birth outcomes. We show that air pollution rises during Yellow Dust outbreaks and that exposure to air pollution during pregnancy has a significant negative impact on birth weight, the gestation weeks of the baby, and the propensity of the baby being born low weight. Public alerts about air quality during pregnancy help mitigate the adverse effect of pollution on fetal health. The results provide evidence for the effectiveness of pollution alert systems in promoting public health. They also underline the importance of taking into account individuals' avoidance behavior when estimating the impact of air quality on birth outcomes. We show that when the preventive effect of public health warnings is not accounted for, the estimated relationship between air pollution and infant health is reduced by more than fifty percent. In summary, air pollution has a deteriorating impact on newborns' health, and public alerts that warn individuals about increased air pollution help alleviate the negative impact.

This paper examines whether access to public transportation reduces the probability of food insecurity for households. The dataset combines information from the Current Population Survey Food Security Supplement (CPS-FSS) and the National Transit Database for the period of 2006 to 2009. I address a potential endogeneity problem using the change in federal governmental transportation funding, the Urbanized Area Formula grants, as an instrument. I find evidence of a negative causal effect of public transportation accessibility on food insecurity. An extra busequivalent vehicle per 10,000 people decreases the probability of food insecurity of households by 0.78 percentage points. In particular, the impact of public transit is more prominent among poor households and poor African-American households. JEL classification: I32; R10

Beginning in 2001, states were given the authority to formulate their own rules on how vehicles are counted toward the asset limit in the Supplemental Nutritional Assistance Program. We exploit differences in timing of the state vehicle asset policy changes to identify their effect on vehicle assets and debts, car ownership, liquid assets holdings, as well as non‐housing wealth. We estimate difference‐in‐differences and household fixed effects specifications and find that liberalizing vehicle asset rules increases vehicle assets of households with a high ex ante probability of program participation. Households also take on more debt to finance their vehicles. The increase in car value can be attributed primarily to less educated single parents who already owned a car before the policy change buying more expensive cars.

provided useful comments. Jie Zhang provided excellent research assistance. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research. NBER working papers are circulated for discussion and comment purposes. They have not been peerreviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.