Characterizing health and behavior among people experiencing homelessness : case study of social norms, seasonality, and COVID-19 in Nashville, TN
Keywords: Environmental Earth System Science.

ABSTRACT This dissertation research seeks to understand how the "homeless" environment, a complex ecosystem comprised of social and biophysical environmental dimensions, is associated with well-being among people experiencing homelessness in Nashville, TN. Specifically, I aim to understand how this environment may affect health and behavior through both direct pathways, such as through environmental exposure, and indirect pathways, such as through the mediating influence of social connections. I begin by empirically assessing environmental (i.e. seasonality) and social (i.e. social support) correlates of self-reported physical and emotional health among unsheltered PEH (Chapter 1). Next, I investigate whether PEH form a group, or social identity around their shared characteristic of homelessness and explore norms of generosity and fairness using an experimental dictator game (Chapter 2) Finally, I use a representative spatially distributed network of a homeless population constructed using my field-generated dataset of N=246 homeless individuals' social networks to estimate the expected mortality from COVID-19 among PEH (Chapter 3). Chapter 1 People experiencing homelessness (PEH) face extreme weather exposure and limited social support. However, few studies have empirically assessed biophysical and social drivers of health outcomes among unsheltered PEH. Social network, health, and outdoor exposure data were collected from a convenience sample of unsheltered PEH (N = 246) in Nashville, TN, from August 2018--June 2019. Using multivariate fixed-effects linear regression models, we examined associations between biophysical and social environments and self-reported general health and emotional well-being. We found that study participants reported the lowest general health scores during winter months—Nashville's coldest season. We also found a positive association between the number of nights participants spent indoors during the previous week and general health. Participants who spent even one night indoors during the past week had 1.8-point higher general health scores than participants who spent zero nights indoors (p < 0.01). Additionally, participants who experienced a conflict with a social contact in the past 30 days had lower emotional well-being scores than participants who experienced no conflict. Finally, women had worse general health and emotional well-being than men. Ecologically framed research about health and well-being among PEH is critically needed, especially as climate change threatens to increase the danger of many homeless environments. Chapter 2 Although society frequently labels people experiencing homelessness (PEH) as a single, marginalized social group—i.e., "the homeless, " it is unknown whether PEH create social identities around their shared characteristic of homelessness. Using a dictator game, we tested whether PEH display in-group bias, a common feature of social groups, toward other PEH (an in-group) compared with housed people (an out-group). We did not observe in-group bias, suggesting that the shared vulnerability of homelessness may not necessarily foster the formation of a meaningful social group. On average, participants allocated 29% of their game endowment to recipients, suggesting that PEH are not entirely selfish and display behavior consistent with dictator game studies across various cultures. Among men, we found a positive association between game allocations the number of emotional and material supports in one's social network, and the opposite among women. Finally, we found that PEH were more generous in the dictator game when they perceived other PEH would also be more generous in an identical scenario, suggesting PEH act in accordance with perceived norms of fairness. Chapter 3 The novel COVID-19 virus has resulted in a global pandemic with catastrophic epidemiological consequences. Yet, the epidemiology of COVID-19 among homeless populations, including prevalence and mortality rates, is not well understood. We also still do not know how the downstream, indirect effects of the pandemic (e.g., lockdowns and local restrictions on food and health services) have specifically impacted people experiencing homelessness (PEH). In this study, we use a field-generated dataset of N=246 homeless individuals' social networks to estimate a complete, representative spatially distributed network of a homeless population in Nashville, TN. We then simulate a COVID-19 epidemic across this social network to estimate the expected mortality from COVID-19 for this population. We observed a 1.5% mortality among PEH due to COVID-19, which is comparable to COVID-19 mortality rates in the general population. Recently, excess morality among PEH as a result of COVID-19 was estimated to be 3%; thus, we theorize that approximately half of these estimated excess deaths are due to COVID-19 infection itself while the other half is due to compounding effects due to disruptions in access to essential services and resources. This suggests that the pandemic has resulted in higher excess mortality due to factors other than COVID-19 infection in homeless populations than in the general population