All major private industry divisions save one had at least a small increase in their average workweek during the decade ending in 1999. The exception was services with no change in average weekly hours.
Despite these increases, average weekly hours for the private sector as a whole actually edged down over the course of the decade. How? The answer lies in the changing industry composition of employment.
In 1989, the goods-producing sector employed nearly a quarter of all production workers and had a workweek of 40.3 hours—well above the average. Ten years later, the sector's workweek had risen, but its share of employment had fallen. At the same time, while the workweek in the service-producing sector had risen a bit, it was still relatively short and the sector's share of employment had increased.
The data on workweeks are produce by the Current Employment Statistics program. Hours data are collected for production or nonsupervisory workers on private nonagricultural payrolls. Read more about employment trends in the 1990s in "Job Growth in the 1990s: a retrospect," by Julie Hatch and Angela Clinton, Monthly Labor Review, December 2000.
Bureau of Labor Statistics, U.S. Department of Labor, The Economics Daily, How seven pluses and a zero make a small minus for working hours at https://www.bls.gov/opub/ted/2001/jan/wk5/art01.htm (visited December 06, 2022).