单项选择题

During the recession, job losses were not equitably shared; employment rates fell more for some groups than others. It is also well-known that job losses were greater among men than among women—the so-called mancession—largely because men had been more likely to work in the residential construction and manufacturing industries that were hit hardest.
What I"m going to reveal is the employment rates separately for married women and unmarried women who were heads of households. Not surprisingly, the latter are somewhat more likely to work. More surprising is that employment rates fell so much more for these unmarried women who were heads of household. Employment per capita fell 4.7 percentage points among the latter, compared with 1.6 percentage points among the former. The job-loss gap associated with marital status turns out to be as large as the more widely recognized job loss gap associated with gender.
Neither group of women had many members working in construction, so the decline of construction cannot explain these differences. An "added-worker effect" has been observed during a number of recessions: more married women worked during a recession than during an expansion because wives sometimes begin work to help replace the income lost by their unemployed husbands.
The employment rate among nonelderly married men fell 4 percentage points, to 83 percent from 87 percent. While that is a large decline by historical standards, it still means that roughly 95 percent of wives whose husbands were employed in 2007 had husbands who continued their employment during the recession. Among the 5 percent of wives who were not so fortunate, roughly two-thirds of them had already been working before the recession and therefore could not react to their husband"s unemployment by starting work. Therefore the added-worker effect is much too small to explain the sharply different job-loss rates by marital status.
What seems to be especially different between married and unmarried women is their propensity to be unemployed for long periods. The point is that married and unmarried women enter unemployment at about the same rate, but unmarried women leave it more slowly. Part of the difference in labor-market experiences has to do with the safety net. Many safety-net programs, like the Supplemental Nutrition Assistance Program, which provides food stamps, and Medicaid, base eligibility on family income. A married woman is usually ineligible for a number of safety-net programs because her family"s income is above the poverty line regardless of her employment status.
Unmarried household heads, on the other hand, are usually the sole breadwinner for the family, and when their income falls to zero, the household income essentially does, too. For this reason, more unmarried women who are heads of households can expect anti-poverty programs to help them when they are out of work than married women can. An unintended but unavoidable consequence of providing someone a cushion when they are without work is that they are provided with less incentive to get back to work. The job-loss gap between male and female is closely associated with ______.