In the 1930s, U.S. eugenics and birth control movements inspired experimentation on Puerto Rican women. Claiming overpopulation contributed significantly to poverty there, the United States initiated a sterilization program in 1938, with an estimated one third of Puerto Rican women of childbearing age sterilized by the 1970s. During the 1950s, Puerto Rican women also served as subjects of research for early oral contraceptives, which contained dangerously high doses of hormones. The program was not reflective of any more general development supporting women's reproductive rights, as women were largely kept ignorant of other real contraceptive choices, and even of the consequences of tubal ligation itself. Rather, it was publicly promoted as an economic solution directly affecting women who would not lose precious time on the job due to childbearing. Women supplied the majority of labor in poorly-paid garment production, and corporations had a vested interest in keeping them working. In addition, authorities hoped that the Puerto Rican experiment could serve as a model for economic development through population control.