with nearly equal shares of men and women (Gill et al., 1992:320–323). Nonwhites now compose about one-quarter of the U.S. population. Middle Series Projections by the U.S. Census Bureau show the minority share of the U.S. population approaching 35 percent by 2020 and 50 percent by 2050 under a given set of assumptions about trends in fertility, longevity, and immigration (Passel and Edmonston, 1992; U.S. Bureau of the Census, 1992).
The 20th century has seen a substantial increase in the years of formal schooling and educational credentials of both the U.S. population and the labor force. The increases have occurred across all gender and racial groupings, although the average levels of educational attainment differ among whites, blacks, and Hispanics. These differences are even more extreme at higher levels of education. The rising educational attainment of the workforce is apparent in recent data. Between 1970 and 1995, the fraction of the workforce with less than a high school diploma declined sharply. By the mid-1990s, 93 percent of whites, 87 percent of African Americans, and 57 percent of Hispanics had received a high school diploma or equivalency certificate (National Center for Educational Statistics, 1997:92). Also, the fractions of the workforce with some college, particularly with four or more years, rose strongly, especially for women, for whom the fraction was near zero at the beginning of the sample period. These trends in educational attainment, however, do not necessarily point to greater diversity of the workforce. For example, the fraction with a high school education—the modal level of educational attainment—appears relatively stable over this period (at approximately 20 percent).
One way to summarize some of the most important trends is with comparisons of life and worklife expectancy for U.S. men and women for selected years since the turn of the century. Table 2.1