It is a revolution which is happening in every developed country, and in some parts of the world - Scandinavia, for instance - it has gone further than here. But Britain is particularly interesting for two related reasons. First, it has pioneered part-time working, which suits the work patterns of women more than it does that of men; and second (partly because, as the chart shows, we have developed part-time employment), it differs from most developed countries in having lower female unemployment than male. Incidentally, we also have the highest proportion of 15-64 year-olds in employment of any European Union country.
The role of women in the workplace was news last week because the Central Statistical Office produced its first comprehensive report on the condition of women in Britain, Social Focus on Women. It acknowledged the progress that has been made during the last 20 years, but pointed out the extent to which women's earnings still lag behind those of men. UN statistics would seem to confirm this (see graph): we are towards the bottom of the equality league - though if one allows for the fact that women work shorter hours, the disparity is not so great. Women receive about 70 per cent of men's earnings, but their rate per hour is 80 per cent of men's.
But there is still the gap. If it is easy to identify the reasons why women have made progress - the trend towards part-time working, the growth of service industries, and, importantly, their better educational performance - it is harder to see why the gap has not narrowed faster. Of course, the fact that many women take some sort of career break to have children must act as some kind of disadvantage in some organisations. But most companies are now abandoning the notion that their staff should be expected to have continuous careers - indeed it is a great convenience to have a mobile workforce - so that should be becoming less of a disadvantage. This suggests that the gap both in pay and in opportunities will continue to narrow.
If that is right, the really interesting questions are not the backward looking ones about the lack of progress, but rather the forward looking ones: in particular, when and where does this feminisation of the workforce stop?
The short answer to the "when?" is: not for a long while yet. The Employment Gazette last week gave some projections of the British labour force up to 2006. It looked at the age profiles of the different regions and predicted where there would be the largest increases in the workforce. For people interested in that, the fastest growth will be in East Anglia and the only areas where the workforce will decline is in Scotland. More striking, though, is the way women will come to dominate the workforce. The number of women in the UK workforce will rise by 10.5 per cent, while the number of men will rise by only 2.3 per cent.
So it is very hard to see this process of feminisation of the workforce slackening for another 10 years at least. The "where does it end?" question is more complex.
Simply increasing the proportion of women in the workforce is bound to have a number of quite dramatic effects. For example, the glass ceiling will, in a number of areas, have to be broken. Some professions, such as solicitors, and some companies, such as the BBC, have a particularly large proportion of young women in professional or executive posts, while their upper ranks remain dominated by men. In 10 or so years' time, there simply will not be sufficient young men to fill those top jobs, whatever social biases remain.
Of course the advance will not be universal. The armed forces, many multinationals, and the House of Commons, may well remain the preserve of men. But the sheer mathematics of labour force growth are so compelling that it is hard to see the glass ceiling remaining in most activities. Of course, many women may decide that there are better things to do that sit up all night in the Commons, but that is a rather different matter.
The next big change will be in the erosion of the distinction between part-time and full-time work. It is pretty much an artificial distinction already, because it measures input rather than output - the amount of work produced by many part-time workers is larger than that of many full- time ones. But as the proportion of women rises further, the distinction will become more blurred. Indeed more and more people, even in white-collar jobs, will be paid by their output rather than by the number of hours they sit at a desk.
As home-working increases, (again a change that tends to suit women better than men) the whole idea of measuring hours worked rather than tasks done becomes a bit absurd. Measuring by tasks done, piecework, has unpleasant connotations for it is redolent of the sweatshops of the last century or the labour troubles in our factories this century. But it does have the advantage that it is more difficult to discriminate against women if the only thing being measured is output.
You can already catch a feeling of the effect of more piecework. In areas where women compete on an absolutely equal basis with men and are paid purely by results, women already have as high, or higher, earnings than men. Barbara Taylor Bradford is probably the highest-paid British author and comfortably out-earns the chairman of even our largest company.
Of course all trends come to an end. At some stage the advance of women will tail off. They will have achieved more or less equal pay, at least on an hourly basis. They will have reached, insofar as they want to, the top jobs. And in doing so, they will have caused a number of structural changes to take place in employment and self-employment practice. How far off is this?
It is, of course, guesswork, but I suspect that we have about another 20 years of rapid change - some time into the second decade of the next century. Thereafter, the issue of women in the workforce will become less contentious, for we will have reached some kind of steady state. There will be lots of other hot topics in social policy, but discrimination in the workplace will have become a relatively small issue. Before the development of the factory system, the vast majority of men and women both worked, though in differentiated roles. In the early dark days of the Industrial Revolution, women also worked in the factories, but the long hours and dreadful conditions of that system led to the various social advances that enabled most women to escape to their homes and families.
In our post-industrial world, where much work can be done on screen and more on a part-time basis, we are going some way back to pre-factory work patterns. The difference is that the rigid gender differentiation of roles of the 18th century and earlier has largely broken down. It will inevitably break down further, whether we like that or not, for the demography of the job market dictates that it must. Meanwhile, we had better get used to it.