 Even with the Jiajing reforms to document migrant workers and merchants , by the late Ming era the government census still did not accurately reflect the enormous growth in population . Gazetteers across the empire noted this and made their own estimations of the overall population in the Ming , some guessing that it had doubled , tripled , or even grown fivefold since 1368 . Fairbank estimates that the population was perhaps 160 million in the late Ming dynasty , while Brook estimates 175 million , and Ebrey states perhaps as large as 200 million . However , a great epidemic that entered China through the northwest in 1641 ravaged the densely populated areas along the Grand Canal ; a gazetteer in northern Zhejiang noted more than half the population fell ill that year and that 90 % of the local populace in one area was dead by 1642 . 
