i can find global_population_growth = 4.0 where? Defines.lua?global_population_growth = 4.0 means that each province will have added 4% of pop completion added to it per month, regardless of existing growths (0.1% will become 4.1% and 10% will become 14% per month). There is no modifier to influence currently generated pop_growth % as far as I know, so you can't "double" the growth of a province based on any existing factors. The only dynamic solution to pop growth is making pops generate pop growth.