The Declining Contribution of Socioeconomic Disparities to the Racial Gap in Infant Mortality Rates, 1920-1970

1. IntroductionGreat improvements in physical health are among the 20th century's most impressive social achievements. In the United States, life expectancy at birth increased by more than 25 years (Atack and Passell 1994), average height increased by about 7 centimeters for native-born white males (Costa and Steckel 1997), and a number of deadly diseases and debilitating illnesses were all but vanquished. As the population's overall level of health improved, racial gaps in health outcomes persisted. Such gaps remain a serious concern for U.S. policymakers (Department of Health and Human Services 2000; Levine et al. 2001; Byrd and Clayton 2002). In large part, this is because physical health is a direct determinant of well being. Additionally, because one's health may influence educational attainment, labor force participation and productivity, and one's children's health, the consequences of intergroup health disparities may be quite far reaching (Grossman 1975; Edwards and Grossman 1979; Currie and Hyson 1999).In discussions of intergroup health differences, infant mortality is a frequently referenced barometer. As shown in and , the overall infant mortality rate (deaths under 1 year of age per 1000 live births) and the absolute (nonwhite-white) racial gap in infant mortality rates fell over time, but nonwhite infants were always more likely to die than white infants. In fact, on average, nonwhite infants were about 75% more likely to die than white infants during the 20th century. When translated into numbers of "excess" deaths, it is clear that the racial gap remained nontrivial even as it narrowed in absolute terms: In 1940, approximately 8900 more nonwhite infants died than would have if they had had the same mortality rate as whites; in 1970, the excess was approximately 8400 infants.1The literature on infant mortality is voluminous and multifaceted, but relatively few studies have systematically examined how racial gaps in infant mortality changed in the early and mid-20th century, choosing instead to focus on more recent data (see inter alia, Rochester 1923; Woodbury 1925; Shapiro, Schlesinger, and Nesbitt 1968; Chase 1972; Shin 1975; Grossman and Jacobowitz 1981; Ewbank 1987; David and Collins 1997; Department of Health and Human Services 2000). Understanding the racial gap and its movement in the earlier period is important for at least three reasons. First, by far the largest improvements in infant mortality, and the largest declines in the black-white gap, occurred before 1970. Historical experience therefore provides perspective on the magnitude of contemporary infant mortality levels, changes, and disparities. Second, the most striking, and puzzling, aspect of the post-1970 experience is that racial disparities in socioeconomic characteristics account for less than half of the racial gap in infant mortality rates (Hecht and Cutright 1979; Miller 2001; Cutler and Meara 2003). We find that this was not always the case; rather, the large "unexplained" portion of the gap emerged gradually in the postwar period. Consequently, researchers and policymakers interested in understanding the origins of the large unexplained residual may benefit from closer empirical scrutiny of the pre-1970 period. Third, for most of the 20th century, prevailing patterns of racial discrimination embedded themselves in the health care system, perhaps compounding the disadvantages that African Americans already faced due to their geographic distribution and relative lack of financial and educational resources. The health implications of racial segregation (and desegregation) have not been adequately documented, especially for the period when segregation was most intense.In this paper, we explore state-level infant mortality data in a framework that sheds light on both the declining overall level of infant mortality and the racial gap. After discussing the interaction of race, history, and infant mortality in the context of a simple model of demand for and supply of health care, we construct and analyze a panel of state-level data for whites and nonwhites. …