probably the median income of the area also goes into it, 1m with low median income might perform at about the same as 800,000 with high median income. Europea

probably the median income of the area also goes into it, 1m with low median income might perform at about the same as 800,000 with high median income. European cities - compared to U.S at least - also maybe have the factor of how long it has been a city to contribute to how much "a city" it seems.