Throughout the past generation, American women were entering the workplace in surging numbers, but since 1990 that number has remained stagnant - with no clear reason as to why.

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The number of women in the workforce remains at 74 percent, the same as it was almost 25 years ago. What is more troubling though, is the United States is seeing European countries exceed it in the number of women finding work. The United States was 27 out of 37 developed countries in terms of women in the workforce according to Organisation of Economic Cooperation and Development.

The United States is the only developed country without a required parental leave, and that has resulted in some women not entering the workforce as rapidly.

"There's only a few countries in the world that do not have any mandatory leave policy, and the ones that don't are not countries we really want to be associated with. They're very poor countries," said Dr. Heidi Hartmann, president of the Institute for Women's Policy Research.

In Europe women can receive from 14 weeks to over a year of paid maternity leave-based on the country.

"The European Union has set those standards of employment, and they find that investing in these subsidies to help women be employed has helped their economy overall," said Dr. Hartmann.

New Jersey is only one of three state's that provides up to six weeks of paid leave for family care.

"As she needs a little more time for family care, she has an additional six weeks of family leave insurance that was added on to the state's temporary disability insurance. Only two other states have done that, California and Rhode Island."

While the rate of women in the workforce remains flat, women are entering the education field in record numbers. Hartmann said many women are staying in academia longer to pursue advanced degrees. She also said stagnant wages and the high cost of child care could be to blame for women deciding to stay home, especially when working doesn't make financial sense.

Between 1985 and 2011, average child care costs rose 70 percent for working moms, after adjusting for inflation, according to the U.S. Census, something also subsidized in many European countries.