ance the evidence points to recent declines in job stability for at least some groups of workers during the first half of the 1990s. How fundamental these changes are depends on whether they reflect the beginning of a long-term trend, a question that can best be addressed by examining other aspects of the employment context.

Changes in the organization of work have made it possible to eliminate many jobs from organizations and may also facilitate their rapid restructuring. We examine two such changes: changes in managerial jobs and the rise in team-based work.

Managerial jobs may well be the ones that have experienced the greatest transformation in their structure in recent years, and their transformation has been the subject of considerable attention from the business press. To understand what has changed, it is sensible to start by describing the characteristics of the "old" internal labor market of managers.

The distinctive characteristic of traditional managerial careers is the existence of a promotion ladder and the notion of moving up it (Rosenbaum, 1984; Baker et al., 1994). Ladders of upward mobility were well defined. One implication of these ladders is that most movement was in the upward direction. Managers either were promoted or stayed where they were. Lateral shifts were very rare; demotions were essentially unheard of.

All observers agree that managers did not face serious risks of layoffs until the late 1970s (MacDuffie, 1996). Nor was pay at risk. Senior managers began the 1980s with the vast majority of their pay package in the form of base or guaranteed pay that did not vary with either their performance or that of the organization (Useem, 1996).

Another aspect of managerial employment systems was the strong bias toward continually increasing the proportion of managerial jobs in the workplace. In 1929, American manufacturing firms employed 18 administrative workers for every 100 employ-