The development of robots has raised the possibility of such a future: the work left to humans will be reduced. For tired office workers, having more leisure time sounds like a good idea.

However, what really matters is not only the total amount of human labor needed in the future, but also how the work will be allocated among the workforce. If modern trends can be used as reference, we have no reason to think that future work will be equally distributed.

In the UK, the average working hours per week have decreased from about 59 hours in the middle of nineteenth Century to 32 hours in 2009. But the average cover up a lot of problems.

Despite the steady trend of women, male trends have changed dramatically. According to the Resolution Foundation, a think-tank, the male income of high paid full-time jobs is 2.5 times the median salary, and these days, their average working hours are slightly more than 20 years ago. Meanwhile, the working hours of full-time men with the lowest wages were greatly reduced.

In addition, the number of part-time low paid men has increased dramatically. 20 years ago, 5% of the low paid men between the ages of 25 and 55 took part-time jobs, and now the ratio is 20%. The analysis of Institute for Fiscal Studies, another think-tank, shows that this phenomenon only occurs in low wage groups. In higher paid jobs, part-time men are still scarce.

This may be a good thing. Unlike the United States, in Britain, the low paid male working hours are traditionally far more than those with highly educated and highly paid workers. Perhaps the labour market has finally become more equal. Men of different backgrounds have similar working hours.

In the UK, government intervention (such as the tax credit and the minimum wage that began about 20 years ago) may mean that low - paid men do not need to work hard for a decent living standard. Unlike the United States, Britain's low skilled men have so far not been completely eliminated by the labour market.

The gender roles within the family may also be converging. Low paid men may choose to take more childcare so that their partners can work again.

But it's impossible to explain everything. The increase in part-time jobs has occurred in two groups of low paid single men and married men, including those with children and no children. Many part-time men seem to be forced to choose, not to choose. According to the official British labor market survey, 1/5 of the men in the part-time job said they could not find full-time jobs, compared with 1/10 of the women who had this idea. For the two groups of men and women, the proportion of involuntary part-time jobs was higher than that before the financial crisis 10 years ago (but lower than the peak level during the recession).

In the past 20 years, the UK's income redistribution welfare system has been done well in terms of ensuring that these employment trends have not created more serious income inequality (except the highest income class). However, employment distribution is still important for people. There is also a problem of underemployment and overemployment in the UK: official figures show that 3 million 400 thousand people want more work time and 3 million 200 thousand people are willing to reduce their wages to reduce their working hours. Underemployed persons are most likely to be waiters or cleaners. Overemployment is most likely to be a doctor or CEO. This implies that the supply and demand of skills within the economy is out of step.

No one has determined how the next wave of automation will affect demand for different skills. Perhaps doctors will get the leisure time they crave. Others may find themselves hotter. But unless we set up a better system to train people to quickly adapt to the work needed by the economy, the future (as now) seems likely to happen: there is too much work left for some, and there are too few people to work.