Today, April 14, is Equal Pay Day – a date selected in 1996 by the National Committee on Pay Equity to represent how far into the year the average American woman must work to earn what the average American man earned the previous year.

The wage gap – currently estimated as 78 cents on the dollar – is a highly contentious figure. One limitation of this 78 cent estimate is that it masks many wage gaps of varying sizes. The wage gap depends on many characteristics of women, such as race, ethnicity, marital and parental status, and sexual orientation. It also depends on their professions and the amount of time they’ve spent in the workplace.

But one characteristic is often overlooked: geographic location. Geography places significant constraints on the choices women can make about work.

Nowhere is this more apparent than in the state where I live and teach: West Virginia.  Last month, the Institute for Women’s Policy Research (IWPR) issued a report that estimated a separate wage gap for each state. West Virginia is not only one of the poorest states, ranking 49th of 50 in median income, it also ranked last in terms of women’s employment and earnings. The average wage gap between men and women is larger in West Virginia than in any other state — 67 percent rather than 78 percent. This means that many West Virginia women are among the poorest of the nation’s poor.

The IWPR report also suggests that this disparity isn’t likely to change anytime soon. Given current trends, the wage gap for West Virginian women is not estimated to close until 2101.

Why do women in West Virginia fare so poorly relative to women in other states? The answer isn’t about “red state” politics or a stubborn commitment to the male-breadwinner model.  The answer has much more to do with geography — and, in particular, with the rural character of the state.

According to a report from the West Virginia Advisory Committee, women living in rural communities face significant obstacles to employment. Job opportunities are scarce and labor markets are not diversified.

In labor markets dominated by agriculture and mining, women are especially concentrated in “pink collar” jobs – low-wage positions in predominately female occupations. In West Virginia, where the state labor market has these characteristics, about 58 percent of women work in the service industry (particularly in education and health care). One in three women in the state works in a low-wage job, placing these women in the bottom 25 percent of the income distribution, compared with about one in six men. This occupational segregation partly accounts for the larger wage gap facing women in the state.

Women in rural communities often face practical obstacles in their careers as well, because access to services such as public transportation, child care, health care, and elder care is limited. These factors also create barriers to educational attainment– only about 18 percent of women older than 25 in West Virginia hold a bachelor’s degree, compared with 28 percent nationwide – which further restricts their career choices.

The data on West Virginia shows that women sometimes operate in more constrained environments or “opportunity structures” than men. This is true in many other rural states and localities, and it is critical for understanding gender-based inequality. We should not attribute the pay gap to women’s choices without acknowledging the limitations of their choice set.

Geography isn’t destiny, but its influence on economic inequality does require a more nuanced policy approach.  Addressing the wage gap requires more than just attention to gender discrimination — it requires changing the opportunity structures that women face.

Erin Cassese is an associate professor of political science at West Virginia University.