In Reply

We thank Pivalizza et al. for the valuable input based on their experiences that they provided on our original article.¹  We agree that one of the potential drivers of gender differences in earnings could be the types of hours worked and the costs and benefits associated with that type of work. Given that after-hour, weekend, and holiday time may be less desirable for many anesthesiologists, employers may need to pay a premium wage to staff their facilities during these times. And, as you argue, it may be the case that women are less likely to work these hours (based on preference or necessity), and this tendency to work traditional hours may account for meaningful differences in earnings.

We are limited by the data we collected in the survey and are therefore unable to examine all of the potential explanations for the gender earnings gap. We also attempted to limit speculation on aspects of the gender wage gap we could not measure by noting that some of the gap may be driven by individual preferences or constraints female anesthesiologists have, while some of it may be employer-driven. We did try to account for the types of facilities in which hours were worked and the percentage of time allocated to various types of care to account for some of the potential difference in the value of the time anesthesiologists are working. Unfortunately, we did not collect data on the times of day or days worked, so we cannot directly test your hypothesis. While we understand that your hypothesis is focused on the timing of call hours rather than on the total number of hours, we do have average weekly call hours and average call hours spent actively providing care. A quick check indicates that including average weekly call hours in the wage regression does reduce the gender earnings gap by $329 (please refer to the coefficient shown in table 7 in our article¹ ) or 0.5% of the total earnings gap.

Future research should continue to explore the important drivers of earnings differences for physicians beyond what we were able to examine in our study.