While researchers are giving increasing attention to the sex pay gap in Jap
an, most work focuses on women's lack of access to long-term employment and
seniority wages, thus neglecting sex-based wage inequality among regular w
orkers in large firms. Analyzing data collected from a sample of regular ma
le and female workers employed by a large, export-oriented Japanese manufac
turing firm, we examine the sources of the sex pay gap among this group of
workers. Consistent with previous research on regular workers in Japan, we
find that age affects the wages of both women and men and that sex differen
ces in age also help to explain the sex pay gap. In addition, however, we f
ind that women's wages but not men's are negatively affected by the percent
age of women in the job and by holding a job that is shared with nonregular
workers. Moreover, we find that women are penalized more than men for thes
e job characteristics. Hence, while female regular workers in Japan may be
relatively advantaged as compared to other employed women, we find that the
y also experience a sex pay gap and that this gap stems in part from the wa
ge penalties associated with working in a predominantly female job.