performed. At the turn of the 20th century, the population of the United States numbered about 76 million people, with just under 40 percent of the population in the civilian labor force. By the year 2000, the total population is expected to be in the neighborhood of 275 million people, with a civilian labor force in the range of 150 to 145 million (about 50 percent of the population). This section presents evidence on some of the salient demographic changes in the U.S. population and the U.S. workforce and presents some indirect evidence on how these changes may influence occupational analysis and classification.
There is no claim that demographic changes, in and of themselves, directly lead occupational classifications to become outmoded. More likely, there are several ways in which demographic changes indirectly shape the occupational structure and occupational classification systems and analysis, and hence merit attention. Demographic change shapes who is available to work in the workforce. Significant changes in the types of workers in the workforce, and more importantly in the types of workers performing various jobs, may point to instances in which traditional occupational classifications are likely to break down. For example, classification systems developed in an era when manufacturing and blue-collar jobs traditionally filled by men predominated may represent this sector of the economy in fine detail and afford much less detail to other occupational arenas, such as clerical work (National Research Council, 1980).
Furthermore, demographic changes may directly shape the changing content and contexts of work, and hence indirectly shape occupational analysis and classification systems. For example, there is also a growing body of evidence (Williams and O'Reilly, 1998; Chatman et al., 1998) that demonstrates that demographic diversity (age, race, gender, etc.) affects the social interactions and processes of groups or teams by altering patterns of communications, cohesion, conflict, and decision making, which in turn affect performance. These performance effects can be either positive or negative, depending on how effectively the intervening social processes are managed. Thus, increased diversity may have an effect on work contexts, content, and outcomes through these group or team processes and their management. In