Great data for the "work smarter not harder" camp:

BERTRAND RUSSELL, the English philosopher, was not a fan of work. In his 1932essay, “In Praise of Idleness”, he reckoned that if society were better managed the average person would only need to work four hours a day. Such a small working day would “entitle a man to the necessities and elementary comforts of life.” The rest of the day could be devoted to the pursuit of science, painting and writing.

Russell thought that technological advancement could free people from toil. John Maynard Keynes mooted a similar idea in a 1930 essay, "Economic possibilities for our grandchildren", in which he reckoned people might need work no more than 15 hours per week by 2030. But over eighty years after these speculations people seem to be working harder than ever. The Financial Times reports today that Workaholics Anonymous groups are taking off. Over the summer Bank of America faced intense criticism after a Stakhanovite intern died.

But data from the OECD, a club of rich countries, tell a more positive story. For the countries for which data are available the vast majority of people work fewer hours than they did in 1990.