Pretty darned good probably. At least to workers.

A team of British researchers spent almost 10 years studying 71,000 working age Britons.

The premise was that automation is advancing rapidly in the industrialized world, raising the spectre of jobless futures for millions. Besides paid income, jobs also provide psychological benefits from production and work satisfaction, as well as generally pleasing social interactions.

But what amount of work produces the optimum mental health for workers?

Researchers probed workers’ life satisfactions, their mental health, how workdays and work patterns changed and what sort of work patterns were most beneficial to their mental well-being,

Not that they were employed to be happy but that might make a good possible match if it improved personal lives as well as, say, work production.

The workers were asked numerous questions including their anxieties, sleep patterns and work assignments and how they might be tied to their mental health.

“We know unemployment is often detrimental to people’s well-being,” said Dr Brendan Burchell, a sociologist at Cambridge University, “negatively affecting identity, status, time use and sense of collective purpose. We now have some idea of just how much paid work is needed to get the psycho-social benefits of employment — and it’s not that much at all.”

Authors of the study, published Thursday in Science Daily, noted that the near future will see artificial intelligence, robotics and big data replacing much of the work currently done by humans, much the way, for instance, copiers replaced clerks once paid to hand-complete copies of official documents like birth certificates.

Dr Daiga Kamer, one of the study’s authors, said:

If there is not enough (work) for everybody who wants to work full-time, we will have to rethink current norms. This should include the redistribution of working hours, so everyone can get the mental health benefits of a job, even if that means we all work much shorter weeks.

The study concluded — wait for it — that the maximal work week for a human was eight hours. There was no more mental or personal satisfaction derived from working more hours or days. One shift was sufficient.

Now, you might ask, what employer wants to hire eight times as many workers and pay their benefits and Social Security, to get the same production?

The answer, of course, is none. That would seriously corrode their mental health. Also financial.