摘要：Objectives. We assessed whether 2 types of public housing—scattered among market-rate housing developments or clustered in small public housing projects—were associated with the perceived health and health behaviors of residents’ social networks. Methods. Leveraging a natural experiment in Montgomery County, Maryland, in which residents were randomly assigned to different types of public housing, we surveyed 453 heads of household in 2011. We asked residents about their own health as well as the perceived health of their network members, including their neighbors. Results. Residents in scattered-site public housing perceived that their neighbors were more likely to exercise than residents of clustered public housing (24.7% of network members vs 14.0%; P < .001). There were no significant differences in the proportion of network members who were perceived to have major health problems, depressed mood, poor diet, or obesity. Having more network members who smoked was associated with a significantly higher likelihood of smoking. Conclusions. Different types of public housing have a modest impact on the health composition of one’s social network, suggesting the importance of housing policy for health. Multiple housing policies aim to reduce concentrated poverty in neighborhoods for low-income residents who receive federal housing subsidies. The US Department of Housing and Urban Development has attempted to disperse concentrated poverty through its Housing Choice Vouchers program and initiatives such as HOPE VI and Choice Neighborhoods, which replace public housing complexes with mixed-income developments. 1 Court cases have instigated housing relocation programs intended to increase access to opportunity. 2,3 Some municipalities have adopted inclusionary zoning policies in which developers set aside a portion of homes to be sold or rented at below-market rates. Policies that deconcentrate poverty may improve residents’ health and well-being. Most prominently, the Department of Housing and Urban Development’s Moving to Opportunity randomized experiment found that recipients of vouchers to move to low-poverty neighborhoods experienced reduced obesity, diabetes, and psychological distress 4,5 and improved mental health and happiness compared with those who remained in public housing developments. 6 One way that public housing may influence health is by shaping social networks. Social networks represent the web of relationships that exists among people; they consist of social ties that link individuals in a social network. 7 Over the past century, social network theories and analytic methods have developed and been increasingly applied in public health. 8–10 Research suggests that multiple factors influence the formation of social ties including similarity between individuals (homophily), having relationships in common, and the frequency and duration of contact with one another. 11–13 Theoretically, public housing may affect social networks by changing the neighbors with whom residents come into contact and the frequency of these contacts. Previous research has shown that residents living in subsidized housing next to more affluent neighbors may have more socioeconomically diverse social networks than individuals living in public housing developments. 14,15 Different public housing arrangements such as clustering housing into projects or scattering units among market-rate developments, may affect the supportive quality and emotional intimacy of relationships within public housing residents’ social networks. 16–21 Social networks and ties have been increasingly shown to influence a wide range of conditions and behaviors including obesity, 22–25 physical activity, 26–31 alcohol and drug use, 32–35 and smoking. 36,37 Researchers postulate that social networks may induce changes in health and behavior through altering social norms and beliefs. 11,38 Studies suggest that social networks’ influence extends beyond a single degree of separation, 22,36 and research on vulnerable populations has highlighted the influence of social network composition on health behaviors. 39,40 Although social networks may be an important mechanism through which public housing policies affect health, to our knowledge, only 1 study has explicitly examined the connection between social networks and health behaviors among public housing residents. Shelton et al. found social network size to be associated with physical activity among Boston public housing residents. 41 We sought to address 2 research questions regarding the potential relationship between public housing policy and social networks and health. First, we asked whether the type of public housing (scattered vs clustered) influenced the composition of adult public housing residents’ social networks with a focus on perceived health and health behaviors of respondents’ social network members. Second, we determined whether characteristics of these network members were associated with residents’ health behaviors. Our study was set in Montgomery County, a Maryland suburb of Washington, DC. Unlike earlier studies such as Moving to Opportunity, in which participants initially lived in high-poverty neighborhoods, in this study the public housing residents live in low-poverty neighborhoods in an affluent county. The median household income from 2007 to 2011 in Montgomery County was $96 000 compared with the national average of $72 000, and the poverty rate was 6% compared with 9% nationally. Public housing residents in Montgomery County live in homes that are either scattered among market-rate housing developments or clustered in small public housing projects. The Housing Opportunities Commission (HOC), the county’s public housing authority, has purchased 670 scattered-site public housing homes through Montgomery County’s inclusionary zoning program. Through inclusionary zoning, developers set aside 12% to 15% of homes to be sold or rented at below-market prices in exchange for a density bonus that offsets the financial loss. In the developments where the HOC has purchased homes created through inclusionary zoning, no more than 5% of residents live in public housing. The HOC also operates 321 public housing homes that are clustered within 7 developments ranging in size from 19 to 71 homes. In these developments, all residents live in public housing, creating microneighborhoods of poorer people. Although both scattered and clustered public housing units are located in wealthy neighborhoods ( Table 1 ), we explored potential differences among residents’ more immediate neighbors. TABLE 1— Sociodemographic Characteristics of Respondents by Housing Type Among Adults Living in Scattered- and Clustered-Site Public Housing: Montgomery County, MD, 2011 Characteristic All Public Housing Clustered Public Housing Scattered Public Housing P Unweighted no. (%) 453 161 (36) 292 (64) Weighted no. (%) 452 153 (34) 299 (66) Mean age,a y 44 44 44 .721 Female,a % 88 87 88 .769 Race/ethnicity,a % Hispanic 15 14 16 .609 Black 69 71 68 .534 Asian 3 3 2 .895 White 13 12 14 .707 Has a spouse or partner, % 18 21 16 .158 Citizen,a % 84 83 85 .556 Language other than English spoken at home, % 27 25 28 .45 Parent lived in public housing, % 21 23 20 .547 Time lived in neighborhood, y, % 0–2 28 30 27 .514 2.1–6 25 27 24 .5 7–11 22 19 24 .249 12–37 24 23 25 .767 Income-to-poverty ratio,a 2011 1.15 1.05 1.19 .131 Unemployed, % 27 24 29 .276 Education, % < high school 36 39 34 .234 Completed vocational school 31 28 33 .282 Completed high school, some college, or associate’s degree 16 13 18 .158 ≥ completed college 17 20 16 .283 Census-tract median income, $ 95 454 92 722 96 866 .134 Open in a separate window Note. Results are weighted to reflect characteristics of the broader Montgomery County public housing family population. aData derived from the county housing authority's annual recertification records. The random assignment of households to scattered and clustered public housing creates a natural experiment. Households are offered homes as homes become available through computerized, rolling lotteries. The strong demand for public housing—with long wait lists and a large difference between public housing and market-rate rent—helps minimize bias in housing assignment. The appendix (available as a supplement to the online version of this article at http://www.ajph.org ) provides detail on the natural experiment, and supplementary Table A demonstrates the comparability of families in scattered- versus clustered-site public housing. With residents of scattered public housing units having greater exposure to higher-socioeconomic-status (SES) neighbors and with the well-established association between SES and health, 42–44 we hypothesized, for our first research question, that residents of scattered public housing would perceive that their network members were healthier. Our second research question explored whether characteristics of public housing residents’ network members were associated with residents’ health. This question did not directly leverage the natural experiment of Montgomery County public housing assignment, but instead examined associations within the entire public housing cohort.
