The pay of middle-class women is catching up fast with their male colleagues, but the poorest females in part-time work are faring much worse.
The hourly earnings of women in full-time jobs rose from 66 per cent of men's earnings in 1974 to 80 per cent by 1992. While the median hourly earnings of men grew by a third between 1973 and 1993, those of full-time female workers grew by more than twice as much in proportional terms, according to Susan Harkness, of the Centre for Economic Performance at the London School of Economics.
Although part-time workers also caught up, the gain was not near as great as for women in full-time professional jobs.
In a paper, The Gender Earnings Gap, published in the latest issue of Fiscal Studies, Ms Harkness says the gap between the highest and lowest earners has grown for both men and women. The "real winners" are highly paid women, who have seen earnings almost double in real terms since 1973, she says. The losers are women in low-skilled, part-time work.
The other losers were the lowest paid men who saw their pay rise by just 18 per cent over the 20 years, whereas the highest paid women enjoyed a 93 per cent increase. Big male earners saw their pay rise by 49 per cent.
Almost 21 years after the Equal Pay and Sex Discrimination Acts, however, there was still a significant pay gap. Ms Harkness adduced two main reasons for women's lower earnings: they may not have the qualifications and "personal attributes" that command high wages, or simply they are unable to elicit the same rewards as men for their skills. Ms Harkness points out that the educational attainment of women vis-a-vis men has improved markedly.
She believes the change has been the result of a combination of three factors: the effect of equal pay and sex discrimination acts; increases in competitive pressure which discourages discrimination; and a rise in the demand for the goods and services that women typically produce.
Liz Bargh, director of Opportunity 2000, said there was clear evidence that more women were occupying managerial positions. More than 30 per cent of managers among Opportunity 2000 members were women. But she acknowledged that most women were still forced to work part time because of a lack of child care.
Figures used by the union-funded Labour Research Department paint a very different picture to that presented by Ms Harkness. The LRD says the gap in pay has narrowed by just 7.9 per cent in 20 years, at which rate "it will take another 55 years before full equality in average earnings is reached".