Part of the problem is that people talk about productivity in the abstract, which is like measuring your height with an invisible ruler and saying "I've gotten

Part of the problem is that people talk about productivity in the abstract, which is like measuring your height with an invisible ruler and saying "I've gotten taller." Once you define a metric, it's easy to measure yourself against it. Lines of code? Easy to measure. Weeks taken to ship something? Easy to measure. Number of features completed on your checklist? Easy, if you made a checklist. None of these metrics are perfect, but they're a heck of a lot better than nothing, or "I don't know". You can iterate, and refine the estimates as you go along. Just make a conscious effort to measure something. Getting actual data trumps all these endless arguments.