When it comes to part-time work, the gender wage gap goes the other way: Women generally out-earn men.

In the last week, we’ve been plucking choice items from the Labor Department’s latest report on women’s earnings, including one post on the evolving gap between pay for women and men.

The numbers in that post were for weekly wages for full-time workers. But some readers questioned whether it was fair to treat all full-time workers as equivalent. Different workers choose to allocate more or less time to their “full-time” careers, decisions driven in part by other commitments like family responsibilities (which still fall primarily, though not entirely, to women). One person might work 60 hours a week and another 35; all things being equal, surely we should expect the former to earn more.

Thankfully the Labor Department also reports statistics on typical weekly pay broken down by hours worked, for workweeks ranging from just a handful of hours to over 60 hours. Let’s take a look at the pay gap by these workweek lengths:

As you can see, among workers who work at least 40 hours a week, men still significantly out-earn women.

But as soon as you drop below that 40-hour-a-week mark, the reverse happens: Most women make more than men who work equivalent hours, with the exception of workers who put in fewer than five hours a week.

There are a few things to consider when puzzling over why these pay gaps might exist.

One is that these pay statistics do not control for what kinds of jobs these workers are in. And the type of work — whether it be education versus finance, doctor versus nurse, manager versus assistant — accounts for a large portion of the variation in the pay that people receive.

Additionally, men and women are not equally distributed amongst these different workweek lengths. Women are much more likely to be in part-time jobs than men. In fact, in 2009, 66.6 percent (about two-thirds) of American workers logging fewer than 35 hours in the typical workweek were women. By comparison, just 45.1 percent of workers logging more than 35 hours a week were women.

In other words,the “typical” workweek length for men versus women is very different. Men who work part-time are deviating from the “male” workweek norm, a fact that may say something about their quality, ambition or priorities, or at the very least how employers view their quality, ambition or priorities. Likewise with women who deviate from the “female” norm and work full-time.