labor market experience of persons with disabilities reflects these trends, and speculates about the demands that are likely to be placed on workers in the next several decades.

Although it would be hazardous to predict what the labor market will be like in the distant future, several of the most important trends have been unfolding for several decades and can be expected to continue in the years to come (Bell, 1973; Piore and Sabel, 1984; Hirshhorn, 1988; Levy, 1998; Wilson, 1997). These trends include a relative shift from goods-producing occupations and industries to the distribution of services, the increasing demand for highly skilled and highly trained labor and the erosion of demand for those with less skill and training, the emergence of new ways of accomplishing work within the firm, and the emergence of alternative work arrangements throughout the economy.

Some of these trends are relatively easy to quantify, for example, the growth of jobs in services. Some are more difficult both to measure and to evaluate, for example, the growth of contingent employment arrangements (Belous, 1989; Polivka, 1996), the putative erosion of job security (Nardone et al., 1997), and the flattening of workplace hierarchies (Osterman, 1988). Also, many of the changes are not quite as dramatic as some analysts claim: much service work is physically demanding and much of it, regardless of the physical demand, is repetitious. All, however, are difficult to translate into a simple set of instructions for assessing functional capacity for work. Indeed, if there is a message to emerge from an analysis of the trends in the labor market, it is that in the contemporary economy, the division of tasks within and among jobs is growing increasingly complex.

As work demands change, the most important characteristic of those capable of thriving may be the ability to do multiple tasks in an overlapping and constantly evolving series of relationships and to be able to adapt to new responsibilities. The problem facing those assessing capacity for work among persons with disabilities is a daunting one: how to assess an individual’s capacity to do a complex mix of tasks now and to learn a new mix later.

The 1950s and 1960s are viewed by some as the halcyon era in the U.S. economy, with high growth rates sustaining unprecedented increases in