Awhile back I wrote about the Ginther and Kahn paper that compared men's and women's rates of hiring to tenure-track positions and promotion to tenure. The paper found that the differences between men and women could be entirely explained by marriage and children: having young children penalizes women but not men. The paper did not explore salary differences, but noted several other studies that found unexplained differences in men's and women's salaries (of on the order of 12%) that persisted even after controlling for similar factors as well as for productivity.
One hypothesized explanation for these differences comes from the work of Linda Babcock:
In one study, eight times as many men as women graduating with master's degrees from Carnegie Mellon negotiated their salaries. The men who negotiated were able to increase their starting salaries by an average of 7.4 percent, or about $4,000. In the same study, men's starting salaries were about $4,000 higher than the women's on average, suggesting that the gender gap between men and women might have been closed if more of the women had negotiated their starting salaries.
This suggests that a remedy for the salary gap might be to encourage women to negotiate for their salaries. But some new work by Babcock and collaborators suggests that things might not be so simple.
Their study, which was coauthored by Carnegie Mellon researcher Lei Lai, found that men and women get very different responses when they initiate negotiations. Although it may well be true that women often hurt themselves by not trying to negotiate, this study found that women's reluctance was based on an entirely reasonable and accurate view of how they were likely to be treated if they did. Both men and women were more likely to subtly penalize women who asked for more -- the perception was that women who asked for more were "less nice".
Interesting (but frustrating) work.