This paper, accepted to the top economics journal &quot;Journal of Political Economy&quot;, demonstrates how the pay gap in lawyers is due to differences in performance, and that &quot;the differential impact across genders in the presence of young children and differences in aspirations to become a law firm partner account for a large share of the difference in performance.&quot;<p>I hope this scientific study will help inform the debate on the gender pay gap, and in particular will show that the view that the gender pay gap is due in part to different aspirations is based in scientific evidence, not prejudice.