Theory and evidence on disaster-induced population displacement have focused on individual and population-subgroup characteristics. Less is known about impacts on households. I estimate excess incidence of household breakup resulting from Hurricane Katrina by comparing a probability sample of pre-Katrina New Orleans resident adult household heads and non-household heads (N = 242), traced just over a year later, with a matched sample from a nationally representative survey over an equivalent period. One in three among all adult non-household heads, and one in two among adult children of household heads, had separated from the household head 1 year post-Katrina. These rates were, respectively, 2.2 and 2.7 times higher than national rates. A 50% higher prevalence of adult children living with parents in pre-Katrina New Orleans than nationally increased the hurricane's impact on household breakup. Attention to living arrangements as a dimension of social vulnerability in disaster recovery is suggested.
Key Words: living arrangements, marital separation, multigenerational relations.
More than three decades ago, Bolin (1976, p. 267) lamented that "the greaterpart of disaster research has focused on complex organizations, the community, or individuals with the family as a unit being given only cursory attention." Tierney's (2007) recent survey of the field of disaster research indicates that this is still largely true, even as more attention to family processes has occurred through an increased emphasis on gender (e.g., Morrow, 1999). The literature on the sociology of disasters provides the insight that social impacts of natural disasters differ according to predisaster socioeconomic conditions, which describe the population's degree of social vulnerability (e.g., Cutter, Boruffi & Shirley, 2003). In the present study, I consider household structure as a social vulnerability characteristic. I estimate the effect of Hurricane Katrina in 2005 on the breakup of New Orleans households following Katrina, considering both the incidence of breakup by household structure and the distribution of those household structures in pre-Katrina New Orleans.
The data and methodological challenges of estimating an elevated incidence of household breakup attributable to the hurricane are considerable. In addressing them, I apply a casecontrol analytical framework to cases from a survey sample designed to be representative of New Orleans households in August 2005 (the Displaced New Orleans Residents Pilot Study, DNORPS; Sastry, 2009b) and to controls from an ongoing national panel survey of households (the Survey of Income and Program and Participation, SIPP; U.S. Census Bureau, 2010) over an equivalent period. In addressing the role of the pre-Katrina household structures, I also use the 2005 American Community Survey data (U.S. Census Bureau, 2007) to compare New Orleans and the United States generally and to evaluate the representativeness of the analytical DNORPS and SIPP samples of New Orleans and U.S. household structures.
BACKGROUND AND CONCEPTUAL FRAMEWORK
Hurricane Katrina's impact on New Orleans began with what Fussell and Elliot (2009, p. 3 83) described as "the largest, most complete urban evacuation ever to occur on U.S. soil." Nigg, Barnshaw, and Torres (2006, p. 113) described the size of the evacuation of the Gulf Coast areas in the path of Hurricane Katrina as numbering 1 .3 million people and remarked on two additional aspects of the Katrina evacuation that made it unprecedented: the sending of evacuees to distant, out-of-state shelters and the duration of the evacuation into "weeks or months" instead of the usual duration measured in "days or a couple of weeks at most" (p. 121). Quarantelli (2006, p. 3) described Hurricane Katrina not as a disaster but as a catastrophe, one of the characteristics of which is that the scale of physical destruction makes it impossible for displaced residents to obtain shelter with nearby relatives and friends. …