From the upcoming Economic Journal,
Women in Britain who work part-time have, on average, hourly earnings about 25% less than that of women working full-time. This gap has widened greatly over the past 30 years. This article tries to explain this part-time pay penalty. It shows that a sizeable part of the penalty can be explained by the differing characteristics of FT and PT women. Inclusion of standard demographics halves the esti- mate of the pay penalty. But inclusion of occupation makes the pay penalty very small, suggesting that almost the entire unexplained gap is due to occupational segregation. The rise in the pay penalty over time is partly a result of a rise in occupational segregation and partly the general rise in wage inequality. Policies to reduce the pay penalty have had little effect and it is likely that it will not change much unless better jobs can be made available on a part-time basis.
So, the part time pay gap is something like 12.5% when you account for the differences between the people doing the full and part time work (note, not the 36% that the Fawcett Society blather on about) and just about zero when you account for the fact that people are doing different jobs.
As pay is, in the end, determined by how many people there are willing and able to do a job as against how many people wish that job to be done (ie, our old friends, supply and demand) it\’s difficult to reject the conclusion that there is in fact no part time pay gap.
And thus no problem to solve.