The physiological subsistence ought to have been much the same everywhere though. If cities had double or higher wages, in the malthusian era that would have to mean that they were usually destroying their recruited populations via infectious disease. The exception would be areas like Manchuria, where they did find significantly higher wages, and explained it by the land having been held at lower density of population, due to Manchu dynasty policies restricting Han colonization in that area. An accession of land seems to be the trigger for a move to sustained higher productivity, such as could spread out into the entire population, not just the wealthy, but disease-vulnerable, urban ones, of that era.