An important part of the gender gap in the salaries of K-12 educator stems from male educators having additional income

This study examines gender gaps in the salaries of K-12 educators. This is an occupation where direct gender discrimination is less likely since salaries are determined by a union pay scale and women constitute the majority of employers. 

Using data from the American Community Survey (ACS), researchers find a gender gap of $12,000 in the personal income of K-12 educators, with only part of this gap stemming from gender differences in administrative positions, graduate degrees, and grades taught. 

In contrast, when the researchers use a dataset of the public salaries of K-12 educators, we find a raw gender gap that is about three times smaller. 

When we directly compare the distribution of annual income for male and female educators between the public salary and ACS data, the researchers find that an important part of the gender gap stems from male educators having additional income outside of their primary teaching salary.