br Conclusion Our findings bolster a prior

Conclusion Our findings bolster a prior study that reports a positive association between political fragmentation and health disparities (Hutson et al., 2012). We show that Hutson and colleagues’ results have external validity to the 1970s and 1980s, a period in which important, and rapid, changes in urban restructuring occurred. In addition, our serial cross-section study design, which controls for clustering of place-level characteristics across time that jointly affect political fragmentation and mortality, yields more precise and policy-relevant estimates than do studies using one point in time. Our use of several time periods, moreover, allows us to detect secular patterns in the magnitude of the difference between white and African-American mortality. Furthermore, unlike earlier work, our analysis provides race-specific estimates between relation between fragmentation and mortality. This race-specific inquiry uncovered a positive relation between fragmentation and all-cause mortality in both whites and African-Americans – although of different magnitudes. Strengths of our analysis include examination of political fragmentation over a 15 year period. Unlike earlier studies of aggregated annual data, our study minimizes confounding by strong secular patterns in mortality and minimizes bias due to unmeasured county factors. We further controlled for county characteristics such as median household income, proportion of some college degree, population density, and proportion of African-American population. Whereas we acknowledge the debate regarding the value of the “proportion African-American” variable in studies of mortality, we concur with the logic of Deaton and Lubotsky (2009) to include it as a control variable since it may capture structural differences across counties in terms of political or health opportunities. We note, moreover, that inference regarding our order BLU 9931 remains robust to its omission. We analyze all counties with a population size at or above 200,000. Whereas previous literature led us to focus on these urban areas, our results may not generalize to suburban or rural areas. Suburban and rural populations in the 1970s and 1980s show distinct patterns of growth, in terms of racial/ethnic and socioeconomic composition, relative to cities (Beale, 1977; Morrill, 1993; Probst, Moore, Glover, & Samuels, 2004). We know of no literature in political science or urban planning that develops predictions about the health consequences of political fragmentation in suburban areas. Given the documented “white flight” from cities to suburbs in the mid-20th century, we encourage future theoretical and empirical development regarding the relations among such migration, political fragmentation, and racial/ethnic health disparities. In addition, we do not identify structural, economic, or social pathways that account for how political fragmentation moves with population health. Based on previous studies (Acevedo-Garcia & Lochner, 2003; Baron & Kenny, 1986; Jargowsky, 1997), we suspect that racial segregation plays a key role that accelerates poverty concentration or income inequality, and in turn increases race-based health disparities. However, the absence of validated variables on segregation or income inequality over this time period did not allow for testing these pathways. We recommend replication of our work using contemporary data with indicators of racial segregation, poverty, and income inequality. Current U.S. Census surveys on these variables include sub-county identifiers (e.g., city) which may allow refined examination of the partitioning of local governmental entities and resources across cities but within a county boundary. Increasing availability of expenditure data on public health services, moreover, may identify a fiscal pathway by which adjacent cities allocate county resources inequitably in ways that may increase race-based health disparities. These extensions to our work may elucidate whether, and to what extent, political fragmentation precedes an increase in race-based health disparities via segregation, poverty, and/or concentration of fiscal resources.