B is the key here. The problem is that number of hours is too often thrown around as a comparison between two different people. I'd argue that arises from the

B is the key here. The problem is that number of hours is too often thrown around as a comparison between two different people. I'd argue that arises from the more frequently asked question of "Is employee A more productive than employee B?" rather than "was employee A more productive on Tuesday or Thursday?" Employers certainly ask the first question when they're looking for salaries to dump.