Differences in the prevalance of extended living arrangements are examined among black, Hispanic, and non-Hispanic white female-headed and husbandlwife households to evaluate the relative merit of the cultural equivalent and cultural variant explanations of extended structure. Results based on logit analyses indicate that the greater prevalence of extended household structure among Hispanics and blacks is related both to cultural circumstances that lead to extended family structure, and the attempt of households to cope with economic hardship. For each of three measures of extended structure, female headship-frequently associated with economic disadvantage-is significantly related to a higher incidence of extended structure. This may also indicate a greater incentive to find surrogate replacements for absent spouses. Persisting differentials among minority households compared to non-Hispanic whites suggest that the cultural variant explanation of extended household structure deserves closer scrutiny to distinguish clearly processual components from structural components in the analysis of family organization among racial and ethnic groups. One of the most dramatic changes in the composition of family households since the mid-sixties is the pronounced increase in the number of families headed by single women. By 1979, 17 percent of all families with children were headed by women, compared to 10 percent in 1970 (U.S. Bureau of the Census, b). This increase, coupled with the precarious economic situation of such households, has attracted the interest of social scientists and policy analysts. Recent social science research has sought to identify and