The impact on the economy of a nation when women join the work force is evident in the United States. Proof of this can be seen in some of the statistics on women in the work force and women owned businesses at the U.S. Department of State's "Quick Stats on Women Workers" here, and "Women in Business: A Demographic Review of Women's Business Ownership" here.
I am taking the liberty to publish the following short section from The Economist, "Economic contribution of women". It shows what is possible for certain countries around the world if women were to join the work force:
"In the next decade nearly 1 billion women are likely to enter the global labour force. But their economic potential is largely unrealised. According to a report by Booz & Company, a consultancy, if female employment rates matched those of men, GDP would increase by 5% in America and 9% in Japan by 2020. The impact would be even larger for developing countries, home to most of the world’s women who lack adequate education and support (social and political). Increasing female employment would increase GDP significantly in countries like India and Egypt, where female labour-participation rates are below 30%. These countries rank low in Booz’s index of women’s economic empowerment."