The nature of work changed in many ways, in many places, between the middle of the twentieth century and the present day. The most important development was the addition of many new regions to the ranks of industrializing countries. In 1970, only about 20 percent of the world’s population was directly involved in fully industrial economies; by 2020, the figure may well be closer to 60 percent. Additions to the ranks of labor also included huge shifts in women’s participation in the formal workforce in many established industrial centers. More tentatively, new questions were raised about older workers as well.