I'm posting the following here instead of General Discussion because it resembles buggy behavior more than a design choice subject to debate. At a certain point in the game, once a few conditions are met, some AI workers get stuck in an interminable Resource Improvement/Cottage loop. This takes place most consistently in the home areas of European civs (likely others as well, I just haven't watched them as closely) once no unimproved tiles remain locally, and fortunately only seems to be done to Bonus Resource tiles. For clarity, what takes place is that workers will build a cottage on a Pasture, then rebuild the Pasture, then cottage again, ad infinitum (or at least until new factors are introduced like yield increases or new route types from techs).
