At this point, the fact that women in the United States earn about about 80 cents to each dollar earned by men is so commonly known that it’s become both a perverse, if slightly tired, punch line and a litmus test in the culture wars.
But there’s plenty of variation under that top-line statistic. The wage gap is worse, for example, for women of color and for all women in prestigious, well-paying fields like finance and law. Even less often discussed: Geography accounts for 0.3 percent of the gap between male and female wages—which doesn’t sound like a lot, but adds up to more than $2 billion a year nationwide. In Montana, women earn 73 cents to the dollar on average; in Louisiana, they earn 69 cents.
One common explanation for the geographical differences is the fact that some states set a minimum wage that is higher than the national minimum wage. Since women make up nearly two-thirds of minimum-wage workers, those states’ policies raise the pay, on average, of female workers. This would seem to suggest that if a women wants to earn more, she can simply pick up and move elsewhere. But a working paper published Monday by three economists—Kerwin Kofi Charles of the University of Chicago, Jonathan Guryan of Northwestern University, and Jessica Pan of the National University of Singapore—complicates that notion.