New numbers show women working full-time in Missouri made 78.1 percent of what men did in 2013.
According to data released Friday by the Bureau of Labor Statistics, the Show-Me State's women earned a median wage of $665 per week, compared to men's $852 in 2013. The state's women's-to-men's earnings ratio dropped slightly from 2012.
Missouri women also made less per week than women nationwide that year.
But regional economist for the Bureau's Mountain Plains region Jacqueline Michael-Midkiff said there are limits in interpreting the data.
"What these numbers do not reflect is a man and a woman in the same job at the same company with the same level of experience. So it's not comparing just apples to apples," she said.
The ratio puts Missouri among the lowest quarter of states for women's earnings as a percentage of men's. However, Michael-Midkiff warns that sampling errors are larger for state data and cautions making too many comparisons.
She said the differences between men's and women's earnings are caused by a variety of factors not controlled for in the data. Those include varying educational attainment, industry trends or time taken off to care for family.
But she said the numbers are important in reflecting changes in society over time.
"There's a lot of interest in these data from equality groups, women's groups, the Women's Bureau in the Department of Labor," she said. "It does show changes over time in that relationship between women's and men's earnings and it's important to look at that."
Michael-Midkiff also said Missouri's women's-to-men's earning ratio "bumped up" to more than 78 percent in recent years after a relatively stagnant period below 77 percent between 2004 and 2011.