Previous research has shown that female hours of work are very persist
ent over women's lifetimes-that women tend to be either workers or non
workers. This paper uses PSID data from 1967 to 1987 to examine change
s in persistence over time. The overall finding is that there is littl
e change in persistence because as women entered the labor force in gr
eater numbers they tended to become continuous workers, replacing cont
inuous nonworkers. Among older women, spells of reduced hours are now
less prolonged (holding constant a fixed effect). Among young women, t
he persistence of hours has increased slightly over time, and patterns
of employment now appear to develop prior to marriage and continue in
to the married years.