From the 1950s to the early 1970s, most women were secondary earners working mainly as secretaries, teachers, nurses, and librarians (pink-collar jobs). From the mid-1970s to the late 1990s, there was a period of revolution of women in the labor force brought on by various factors, many of which arose from the second-wave feminism movement. Women more accurately planned for their future in the work force by investing in more applicable majors in college that prepared them to enter and compete in the labor market. In the United States, the female labor force participation rate rose from approximately 33% in 1948 to a peak of 60.3% in 2000. As of April 2015, the female labor force participation is at 56.6%, the male labor force participation rate is at 69.4%, and the total is 62.8%.A common theory in modern economics claims that the rise of women participating in the US labor force in the 1950s to the 1990s was caused by the introduction of a new contraceptive technology, birth control pills, as well as the adjustment of age of majority laws. The use of birth control gave women the flexibility of opting to invest and to advance their career while they maintained a relationship. By having control over the timing of their fertility, they were not running a risk of thwarting their career choices. However, only 40% of the population actually used the birth control pill. That implies that other factors may have contributed to women choosing to invest in advancing their careers.
One factor may be that an increasing number of men delayed the age of marriage, which allowed women to marry later in life without them worrying about the quality of older men. Other factors include the changing nature of work, with machines replacing physical labor, thus eliminating many traditional male occupations, and the rise of the service sector in which many jobs are gender neutral. Another factor that may have contributed to the trend was the Equal Pay Act of 1963, which aimed at abolishing wage disparity based on sex. Such legislation diminished sexual discrimination and encouraged more women to enter the labor market by receiving fair remuneration to help raising families and children. At the turn of the 21st century, the labor force participation began to reverse its long period of increase. Reasons for the change include a rising share of older workers, an increase in school enrollment rates among young workers, and a decrease in female labor force participation.The labor force participation rate can decrease when the rate of growth of the population outweighs that of the employed and the unemployed together. The labor force participation rate is a key component in long-term economic growth, almost as important as productivity. A historic shift began around the end of the Great Recession as women began leaving the labor force in the United States and other developed countries.