![Workers leave the GM plant in Janesville, Wisconsin, after the last vehicle, a black Chevy Tahoe, rolled off the assembly line December 23, 2008 after manufacturing trucks, automobiles, SUVs, and tractors since 1919.](https://www.brookings.edu/wp-content/uploads/2024/06/Janesville-Assembly-Plant-final-day-12-23-08.jpg?quality=75&w=500)
![Workers leave the GM plant in Janesville, Wisconsin, after the last vehicle, a black Chevy Tahoe, rolled off the assembly line December 23, 2008 after manufacturing trucks, automobiles, SUVs, and tractors since 1919.](https://www.brookings.edu/wp-content/uploads/2024/06/Janesville-Assembly-Plant-final-day-12-23-08.jpg?quality=75&w=500)
Research
BPEA | 1991 No. 21991, No. 2
IN 1970, when Robert Hall asked, “Why Is the Unemployment Rate So High at Full Employment?”t he unemployment rate for adult men stood at 3.5 percent. That rate, which had been substantially below that level throughout the late 1960s, would climb to 4.4 percent in the recession of 1971. More recently, after the longest economic expansion of the postwar period, the unemployment rate of prime-aged men in the late 1980s settled at just below 5 percent of the labor force. What changes in the American labor market led to this apparent secular increase in the natural rate of unemployment? Twenty years later, we revisit Hall’s question and turn up some new answers.