Why the compensation gender gap?

Sasso and colleagues reported an interesting study in Health Affairs on a topic of great interest: gender gap in physician compensation. It has been contended that because women enter primary care more often and work fewer hours, their compensation tended to be lower. They studied starting salaries of residents in NY state leaving residency programs between 1999-2008. They found a diverging gap with male physicians earning $16,819 on average (up from $3600 in 1999)more than female physician after accounting for specialty choice, work hours, practice setting etc. The compensation was self-reported and some of the information was based on ‘anticipated’ income in addition to estimating averages since some compensation was reported in a range rather than an absolute number. The study confirmed the greater proportion of women who planned to devote fewer than forty hours per week to patient care (38.1 percent versus 24.5 percent of men). 
Comment:The authors admit that it seems unlikely that discrimination has actually increased recently and postulate that women tend to gravitate towards jobs offering more flexibility and family friendly atmosphere and are willing to trade salary for non-monetary benefits.