This paper addresses whether there are productivity differences between men and women among blue-collar workers. We compare the wages under piece- and time-rate contracts of men and women working in the same occupation in the same establishment in three countries: the U.S., Norway, and Sweden. The findings are summarized in four points. First, the gender wage gap is smaller under piece- than under time-rate work. According to the interpretation put forth here, two thirds of the gap at the occupation–establishment level is due to productivity differences, while one third is not “accounted forâ€, but could be due to discrimination or experience or other factors. Productivity differences between sexes in typically male-dominated blue-collar industries are however very small, of 1–3%: Sweden 1%, U.S. 2% and Norway 3%. Second, in age groups where women on average have extensive family obligations, the wage gap is larger than in other age groups. Third, under time-rate work, the wage gap is more or less independent of supposed occupation-based productivity differences between men and women, while under piece-rate work, the wage gap mirrors quite closely assumed productivity differences, with women receiving a wage premium in female-advantageous settings and a penalty in male-advantageous settings. Fourth, in contrast to Sweden, in Norway and the U.S. women sort more often into piece-rate work than men.
