There has been done large amounts of research on heavy overtime's effect on the productivity of software developers. It doesn't take very much overtime for pro

There has been done large amounts of research on heavy overtime's effect on the productivity of software developers. It doesn't take very much overtime for productivity to absolutely plummet. We're not talking just a small time drop here. Rather it's a free fall of 80% or so. This means that even if an engineer works 120 hours every week, he will still not be as productive as if he worked the standard 40-50! More goofing-off time, running errands during work, an extreme increases in defect rates etc, are just some of the reasons. Steve McConnel discusses this at length in his 1996 book "Rapid development", citing large amounts of case studies, books and other research. The irony is that these guys who give the bravado laden "quit the whining, put in the hours" speech, are actually reducing their time-to-market, while simultaneously destroying their developers!