C

  Women earn less than men. For example, in 1988 the hourly wages of women in the U.S. were 16% less than those of men. The gap between male and female incomes varies (变化)with age. The gap between the labor incomes of young women and young men is much smaller than that between middle-aged women and men. It is also clear that jobs in which women are concentrated (集中) pay less. The larger the number of workers who are women is, the lower the average wages are.
  Why do women earn less than men? Is the cause of the gap that women are looked down upon? If so, the government has to intervene (干涉), to force the employers to pay equal wages to equal jobs. However, there is no agreement among economists (经济学家) about the causes of the gap. One view argues that women have chosen low-paying jobs in which workers enjoy the freedom of entering and leaving the labor, which reduces their years of experience relative to men. Other people say the gap can also be explained by the difference in educational background. It is just the difference that cause the difference in productivity between men and women.
  Much of the gap, however, has not been fully explained. It might be the result of some bias against women. What would happen if the government did intervene to increase the wages paid to women? One possibility is that incomes for women as a group might actually decline (下降). An increase in wage decreases the demanded (被需求的) quantity of labor input, and then the rate of hiring new workers declines. The result will be a surplus of labor.