This wonderful Rebels and Revolutionaries in North China, 1845-1945 by Elizabeth J. Perry, is a brilliant study of China's social history. It would be hard to find a book that addresses itself more squarely to the great task of making contemporary China and late imperial China historically comprehensible in term of each other.
Looking back on the late Imperial period, this book discusses how poor and precarious environmental conditions in the countryside of the North China Plain led to the emergence of survival strategies such as banditry, "hederodox" religious groups, secret societies, militias, etc. These groups, constituted outside of state reaches, provided ready-made rebel groups to be mobilized en masse for anti-state rebellions.
This book has really helped to shape my academic path.