The incidence of evening and night work declined sharply in the United Stat
es between the early 1970s and the early 1990s, while the fraction of work
performed at the fringes of the traditional regular working day grew. This
secular decline did not result from industrial shifts or demographic change
s. It was greatest at the upper end of the wage distribution, slowest among
workers in the lowest quartile of wages. The observed changes are explaine
d by a model that views evening/night work as a disamenity, with rising rea
l earnings leading workers to shift away from such work in the presence of
technical change.