This volume contributes to a large literature on job stability and job security by offering a set of closely related papers that attempt to measure recent trends in the United States. Most earlier literature found little change in job stability and job security during the 1980s, seeming to contradict public and media perceptions of a sharp decline in both. The present volume traces its origins to a conference at the Federal Reserve Bank of New York in fall 1996, at which conflicting evidence on trends in the early 1990s was presented. A follow-up conference sponsored by the Russell Sage Foundation encouraged the authors to update their findings through the mid-1990s and to reconcile differences across data sets and methodologies. After review by anonymous referees, 12 papers were collected in this volume. All of them are written by distinguished authors who have contributed previously to this literature.