A new study in the American Journal of Political Science suggests females are better lawmakers than men:

according to a forthcoming study in the American Journal of Political Science—because women also rank as the most effective lawmakers in the land.

The research is the first to compare the performance of male and female politicians nationally, and it finds that female members of the House rout their male counterparts in both pulling pork and shaping policy. Between 1984 and 2004, women won their home districts an average of $49 million more per year than their male counterparts (a finding that held regardless of party, geography, committee position, tenure in office, or margin of victory). The spending jump was found within districts, too, when women moved into seats previously occupied by men, and the cash was for projects across the spectrum, not just “women’s issues.”

A similar performance gap showed up in policy: Women sponsored more bills (an average of three more per Congress), cosponsored more bills (an average of 26 more per Congress), and attracted a greater number of cosponsors than their colleagues who use the other restroom. These new laws driven by women were not only enacted—they were popular.

Two interesting findings. Some might argue these days whether pork is a good measure of “effectiveness” but sponsoring and passing laws seems pretty important.

The next question is why this is the case. Here is what the study concludes:

So are women just innately better politicians? Probably not. More likely, say Berry and Anzia, female politicians are better than men because, as in other fields, they simply have to be. More than 90 years after the first woman was elected to Congress, female politicians still hold less than a fifth of all national seats, and do only slightly better at the state level. In order to overcome lingering bias against women in leadership positions, those women must work that much harder to be seen as equals.

The authors seem to think this effect will go away in coming decades as more women are elected to office. One way to test this idea now that female American legislators have to be better in order to get elected to office is to look at similar measures of effectiveness in national legislatures with greater proportions of women. In countries where the number of men and women are more equal, is there still an effectiveness gap? Did other nations experience a similar pattern as women increased in numbers in the legislature?

It will be interesting to watch the discussion about these findings.