As I'm currently in the middle of research trying to get to the productivity of programmers, my first question (since the one-day caveat has already been pointe

As I'm currently in the middle of research trying to get to the productivity of programmers, my first question (since the one-day caveat has already been pointed out) is they say they're more productive, and they have incentive to. Were they actually more productive? Are there productivity measures in place for each employee? (This was most of the HQ staff, so not all were programmers/knowledge workers.)