33 times as likely as cities in the South to have female-headed families.The sex ratio was only significant in 1990. In 1990, as the number of men for every 100 women increased the percentage of female-headed families declined. Thus indicating that the availability of men in general (regardless of their employment status) was an important determinant of family structure. The results of the cross-sectional models in Table 3 provided tentative support for the second hypothesis, at least in terms of male unemployment. Both indicators of employment dislocation, the male unemployment rate and the percentage of males that worked part of the year, had different effects on the percentage of female-headed families. In the 1980 and 1990 models male unemployment had a positive effect on female-headed families while male part-year unemployment had no effect. In contrast, in 1970 the percentage of part-year males had a negative effect on female-headed families and the male unemployment rate was not significant. From these cross-sectional models of determinants of female-headed families it is apparent that in terms of employment dislocation, male unemployment was important only in 1980 and 1990. The results for 1970 indicate that employment dislocation was not an important factor in determining the percentage of female-headed families in large cities. These results offer tentative support for the hypothesis that after 1980 employment dislocation had a positive effect on the growth of female-headed families. Clearly, there were different factors operating in the decades preceding 1980 and 1990 than in the 1960's (decade preceding 1970). The next step in this analysis is to determine if trends in family structure were due to differences in the industrial and economic composition of the cities or to decade differences.This is accomplished in Table 4 with the results based on a stacked or concatenated file of data from 1970, 1980, and 1990 for each city....
