The Timing of Work Time Over Time

The incidence of evening and night work declined sharply in the United States between the early 1970s and the early 1990s, while the fraction of work performed at the fringes of the traditional regular working day grew. The secular decline in evening and night work did not result from industrial shifts or demographic changes. It was greatest at the upper end of the wage distribution, slowest among workers in the lowest quartile of wages. The observed changes in timing are consistent with and magnify the increase in wage inequality in the U.S. that occurred during this period. They are easily explained by a model that views evening/night work as a disamenity, with rising real incomes causing workers to shift away from such work in the presence of only neutral technical change in the profitability of work at different times of day.