156 SOCIAL SCIENTIST questions that are more pertinent than others may be pinpointed. Why do women get paid less for the same type of work? The theory of wage determination which one most commonly encounters in economic literature is the marginal productivity theory of distribution which says that factors "of production get paid according to their marginal product. This theory states that wage differences can be explained in terms of productivity differences. Thus if the women workers are only half as productive as men, their wage cannot exceed half as much.4 Productivity Difference But is it indeed true that women are less productive than men and uniformly so? Long ago it was conceded that while there were differences in productivity, there were other aspects to be considered. A distinction was drawn between three type of occupations: (1) female occupations which are exclusively entered by women; (2) male occupations in which females do not overstep the lines; and (3) mixed occupations in which are found both men and women. According to Edgeworth, not only will women's earnings in female occupations be less than men's earnings in exclusively male occupations but will be lower also in mixed occupations. Though he makes a distinction between rate of pay and weekly earnings, to say that while the rate may be the same for men and women, the weekly earnings will not be the same is a fine distinction which does not help us very much to clarify matters.8 But under the regime of perfect competition assumed by Edgeworth, if women arc as productive as men in mixed occupations they will be substituted for men and there can be no mixed occupation as long as female labour is cheaper than male labour. In fact as long as there arc mixed occupations where both male and female workers are employed, the wage rate should be uniform throughout all the occupations. Then male occupations should be so called not because the male wage is higher than female wage but because only male labour is employed in that occupation. The same would apply to female occupation. This can be demonstrated with the help of diagram I. DIAGRAM I: COMPETITIVE WAGE DISCRIMINATION (a) Male Occupation (b) Mixed Occupation (c) Female Occupation