Family homelessness has been a persistent concern in the United States since the 1980s. (Bassuk, DeCandia, Beach, & Berman, 2014, pg. 9). Today, more than a third of the individuals experiencing homelessness live in families with children (Henry, Watt, Rosenthal, & Shivji, 2016). Members of families experiencing homelessness face many personal health risks. Adults in homeless families have elevated rates of HIV/AIDS and tuberculosis (Kerker et al., 2011). Homeless mothers experience disproportionately high rates of depression (Bassuk, Buckner, Perloff, & Bassuk, 1998; Weinreb, Buckner, Williams, & Nicholson, 2006). Homeless children are more likely than others to experience asthma (Cutuli, Herbers, Rinaldi, Masten, & Oberg, 2010), obesity (Schwarz, Garrett, Hampsey, & Thompson, 2007), and cognitive and behavioral difficulties (Yu, North, LaVesser, Osborne, & Spitznagel, 2008).

Family housing instability is also costly to American society at large, though Kertesz et al. (2016) highlight the moral and strategic limits of addressing the issue on financial rather than humanitarian grounds. Contributing to this cost is the price of emergency shelter. Culhane, Metraux, Park, Schretzman, and Valente (2007) found that short-term and long-term shelter stays for families in Massachusetts cost $10,900 and $48,500, respectively. Similarly, Gubits and colleagues (2015; 2016) report that families who received usual care in 12 communities across the country used housing and service assistance costing approximately $30,000 and $41,000 over 20 and 37 months, respectively. Children experiencing homelessness also enter foster care at higher rates than their peers (Zlotnick, 2009). In a Pennsylvania-based study, Perlman and Willard (2012) estimated that foster care expenses related to child homelessness cost that state more than $148 million annually. Furthermore, children in homeless families receive more emergency room health care than do their housed counterparts (Shinn et al., 2008).

The Federal Interagency Council on Homelessness set a goal of ending family, youth, and child homelessness by 2020 (USICH, 2015). This effort is partly served by preventing returns to housing instability among families leaving homelessness. However, allocating limited resources to families who will return to homelessness without them is difficult. A minority of low-income families experience homelessness, and most experience single, short-lived episodes (Culhane et al., 2007). Furthermore, studies show that families with long-term housing subsidies are even less likely to return to homelessness than families without subsidies (Gubits et al., 2015; 2016). Supporting housing stability through efficient allocation of housing or other resources requires understanding why some families return to instability when most do not. It also requires understanding why some families return to instability despite the advantage of long-term housing subsidies.

The present study attempts to address the following questions. First, can observable family characteristics explain why families return to housing instability? Second, do families who return to housing instability despite long-term housing assistance observably differ from families who return without such assistance? Because previous studies show large associations between long-term subsidies and housing stability, it is important to understand whether families receiving such assistance face housing barriers above and beyond housing affordability. Second, can those factors be used to efficiently allocate housing or other resources to families most likely to return to housing instability? Improved allocation does not replace the need to address structural drivers of housing instability like unaffordable housing or limited employment opportunities (Shinn, Baumohl, & Hopper, 2001). However, it may assist a particularly vulnerable group of families to stabilize after an episode of homelessness.