American metropolitan areas have experienced rising residential segregation by income since 1970. One potential explanation for this change is growing income inequality. However, measures of residential sorting are typically mechanically related to the income distribution, making it difficult to identify the impact of inequality on residential choice. This paper presents a measure of residential segregation by income, the Centile Gap Index (CGI), which is based on income percentiles. Using the CGI, I find that a one standard deviation increase in income inequality raises residential income segregation by 0.4-0.9 standard deviations. Inequality at the top of the distribution is associated with more segregation of the rich, while inequality at the bottom and declines in labor demand for less-skilled men are associated with residential isolation of the poor. Inequality can fully explain the rise in income segregation between 1970 and 2000. Copyright 2009 The Author. Journal compilation International Association for Research in Income and Wealth 2009.

Abstract:"Chilling effects" are a popular explanation for low program take-up rates among immigrants, but the effects of an icy policy climate are inherently hard to measure. This paper finds robust evidence that heightened Federal immigration enforcement reduces Medicaid participation among children of non-citizens, even when children are themselves citizens. The decline in immigrant Medicaid participation around the time of welfare reform is largely explained by a contemporaneous spike in enforcement activity.The results imply that safety net participation is influenced not only by program design, but also by a broader set of seemingly unrelated policy choices.

for sharing data. Wendy Magoronga and Tianyue Zhou 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.

To what extent do differential levels of investment in public health inputs explain observed differences in health outcomes across socioeconomic and racial groups? This study investigates the impact of 3,700 projects that were part of a widespread Federal initiative to improve sanitation infrastructure on U.S. Indian reservations starting in 1960. Sanitation investment substantially reduced the cost of clean water for households, leading to sharp reductions in both waterborne gastrointestinal disease and infectious respiratory disease among Native American infants. The sanitation program was quite cost-effective, in part because improvements in the overall disease environment also reduced infectious respiratory disease among nearby white infants. Despite the health externalities, Federal sanitation interventions explain almost forty percent of the convergence in Native American and white infant mortality rates in reservation counties since 1970. Abstract: To what extent do differential levels of investment in public health inputs explain observed differences in health outcomes across socioeconomic and racial groups? This study investigates the impact of 3,700 projects that were part of a widespread Federal initiative to improve sanitation infrastructure on U.S. Indian reservations starting in 1960. Sanitation investment substantially reduced the cost of clean water for households, leading to sharp reductions in both waterborne gastrointestinal disease and infectious respiratory disease among Native American infants. The sanitation program was quite cost-effective, in part because improvements in the overall disease environment also reduced infectious respiratory disease among nearby white infants. Despite the health externalities, Federal sanitation interventions explain almost forty percent of the convergence in Native American and white infant mortality rates in reservation counties since 1970.3

American metropolitan areas have experienced rising residential segregation by income since 1970. One potential explanation for this change is growing income inequality. However, measures of residential sorting are typically mechanically related to the income distribution, making it difficult to identify the impact of inequality on residential choice. This paper presents a measure of residential segregation by income, the Centile Gap Index (CGI) which is based on income percentiles. Using the CGI, I find that a one standard deviation increase in income inequality raises residential segregation by income by 0.4-0.9 standard deviations. Inequality at the top of the distribution is associated with more segregation of the rich, while inequality at the bottom and declines in labor demand for less-skilled men are associated with residential isolation of the poor. Inequality can fully explain the rise in income segregation between 1970 and 2000.