The gender gap doesn’t bring out the best in journalists.  With important exceptions, articles on the subject are padded with overly broad statistics, cherry picked research, a myopic view of men and women as lone economic actors, over-credulous references to Sweden, and most insidious of all, an implicit, never-argued assumption that in a just world (i.e. Sweden) women and men would reveal almost exactly the same preferences.  A piece that appeared in Sunday’s New York Times Upshot section “The Motherhood Penalty and the Fatherhood Bonus” by Claire Cain Miller, is a fine example of the genre.

The jumping off point of the piece will be familiar to anyone who has kept a casual eye on gender gap research. Mothers earn less than fathers with similar credentials and laboring in similar occupations.  Citing research by sociologist Michelle Budig, Miller notes that “childless, unmarried women earn 96 cents for every dollar a man earns, while married mothers earn 76 cents.” Men, on the other hand, get a parenthood bonus.  Their earnings go up when they become fathers.

Now, there are two plausible reasons for the motherhood penalty and fatherhood bonus. One is that women behave differently than men when they deal with the inevitable tradeoffs between jobs and children.  That position is certainly consistent with Budig’s finding that men increase their work hours after becoming a parent while women reduce theirs—not to mention mother’s oft-repeated preference for part time over full time employment. Miller, however, seizes on the gender gap literature’s preferred explanation: The gap is caused by discrimination against women, or in this case, “old fashioned notions of parenthood.” Employers remain suspicious of working mothers, she believes, while they are forever patting working dads on the back with raises and promotions.

Miller relies on two studies to make her argument. One is an experiment in which subjects were asked to evaluate the competence of different job applicants and found that they would be more likely to “hire” fathers than mothers. The fact that the  study’s primary subjects were 192 college undergrads, that is 19 to 29 year olds who have never had a full time job, much less hired anyone, goes unmentioned.  However, the study also sent out hundreds of resumes to employers and found that childless women and fathers got more callbacks for job opportunities, which lends some credence to the discrimination argument. More probing is Miller’s other source, a paper by Budig that digs into survey data from 1979 to 2006.  Controlling for a number of variables (though not men and women’s preferences; with few exceptions researchers rarely do) she still finds an unexplained penalty that she concludes, relying in good measure on the aforementioned study of 192 undergrads and 300 employers, should be chalked up to “stereotypical gender expectations.”

Of course, such a bias is possible, but it does raise a question: Why are employers so much more hung up on working mothers than their fellow Americans who have become increasingly blasé about them? And how to explain the results of a paper published just last month by Ipshita Pal and Jane Waldfogel showing over the past two decades the motherhood penalty has declined for married mothers? They now make only 3% less than childless women.  For unmarried mothers, the penalty has increased sharply—to 10.5 percent. Budig herself finds that the top 10% of female earners, the large majority of them married, actually experience no motherhood penalty at all and at the very top, they actually see a bonus. Miller doesn’t mention Pal and Waldfogel’s study and it’s easy to see why: If married mothers have experienced a decreased penalty vis a vis single mothers, then there goes the theory that Archie Bunker employers have it in for working moms.

Miller’s omission is not surprising. Gender gap journalism often shies away from just how big a role marital status plays in all of its percentages. “Low income mothers pay the biggest price” for motherhood, she says citing Budig.  No kidding.  Low-income jobs have less flexibility. Just as importantly, low-income mothers are disproportionately unmarried.  Married mothers can divvy up the laundry, the PTA meetings, and doctors appointments with their children’s resident dad. They also have the advantage of a second income. Terms like “motherhood penalty” and “fatherhood bonus” disenfranchise mothers who freely choose to reduce their work. It also suggests men and women disadvantage or benefit only themselves, but that is plainly untrue for married parents.  When a husband earns more partly because his wife’s hours allow her to pick up the kids, or, of course, vice versa, his or her “bonus” neutralizes his or her “penalty” in ways that render the terms misleading. Unmarried parents who have no joint bank accounts are on their own.

For fathers, too, marital status dramatically changes the numbers. Budig concludes that while higher-income men get a big daddy bonus, “parenthood . . . does not benefit lower-wage working men at all.” She mentions, though only in passing, that higher-income men are almost always husbands as well as fathers; lower wage fathers often aren’t. Researchers have long known that married fathers earn more than childless, never married, and divorced men. In fact, the marriage bonus is larger than the fatherhood bonus: “Married men who become residential fathers receive wage gains of around 4 percent, above and beyond the marriage premium of 7 percent,” writes Alexandra Killewald in an article in the American Sociological Review.  Unmarried fathers, whether they are living with their kids or not, get neither.  We can’t know for sure whether that’s simply because of a “selection effect,” that is, whether men who marry are simply more likely to be emotionally stable and reliable in ways that also make them more productive employees. But there is enough support for the idea that something about marriage improves men’s productivity to make it essential to the fatherhood bonus discussion.

In her conclusion, Miller gestures towards the promised land of Sweden, a required feature of gender gap journalism. There’s no question Sweden has all sorts of enviable benefits for working mothers including paid maternity and paternity leave and subsidized child care. Yet, the broad picture for working parents is remarkably similar to the United States. Yes, the wage gap is smaller in Sweden than in the United States, as you would expect in a country with greater compression between top earners (more likely to be men) and bottom (more likely to be women). But the motherhood penalty and fatherhood bonus are alive and kicking in Scandinavia. Mothers still work significantly fewer hours than fathers. According to the OECD, the pay gap between Swedish men and women grows from 15 to 21% once the children arrive on the domestic scene. In more than a third of couple-families with young children only one parent works full-time; the full timer is almost always dad.

Taken all together, the available research presents not what Miller calls “a clear-cut look at American culture’s ambiguous feelings about gender and work” but evidence of men and women’s different preferences across cultures and the limits of parity, particularly in a society where single parenthood is commonplace.  But don’t expect to read about any of that in the continuing flow of gender gap journalism.