In Britain in the 1840s, a campaign to reduce the length of the working day in factories from 12 hours to 10 prompted predictions of disaster. One parliamentarian called the idea “dangerous” while another warned such “mistaken philanthropy” would prevent workers from providing for their families.

But in 1846, parliament heard the results of an experiment run by an owner of large mills in Manchester and Preston. When he reduced the working day to 11 hours, he found production volumes remained the same and the quality of work improved. “It is, I believe, a fact not to be questioned that there is more bad work made [in] the last one or two hours, than the whole of the first nine or 10 hours,” he said.

Similarly, when Henry Ford reduced the working week in his car factories from six days to five with no cut in pay in 1926, the decision followed several years of experiments which had assured him production would not suffer. “We can get at least as great production in five days as we can in six, and we shall probably get a greater, for the pressure will bring better methods,” he said.