Marriage and children have a detrimental effect on a woman’s earnings but can help a man’s, a report from the Employment Policy Foundation says.

Single women on average earn more than their single male counterparts a big change in the past 20 years. In March 1981, single women earned only 93 cents to every dollar a man earned. By 2001, women earned 101.6 percent of single men’s hourly pay.

Women without children, whether single or married, also improved their earnings.

Married men, however, fare best. When looking at men 30-34, those with wives made 15 percent more than single men and 8 percent more than single women. Some of this may be attributable to the “housework effect,” the report said.

Women spend 14.2 hours per week on household chores, compared with 7 hours for men, the survey states. This may contribute to married men’s earnings advantage in that if someone else is keeping house, they can be more focused on a career.