I was thinking, it might be the cultural tendency to make really long work weeks / hours, but spend a lot of those hours slacking off (see also the thread about the boss-detector arduino thingy). As if they're paid for time, not work.

Unions, organized crime, greedy capitalists, environmental and worker safety regulations, and/or Baumol's cost disease, depending on who's answering the question

Europe has all of these, and their unions and regulations are substantially stronger even.