supply and demand, page-22

The beginning of capitalism when farmers for the first time have a "title" over their land.
Rent it, sell it, mortgage it, whatever.
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Issued in January 2013, China's first policy document for the year, dubbed the No.1 central policy, stated that the government will create policies to speed up rural land transfers and grant more subsidies to large-scale landholders, family farms and rural cooperatives to encourage the establishment of large-scale and specialized farming.

http://english.peopledaily.com.cn/90882/8166345.html

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Bigger farms are more profitable and smaller farmers have state support to go to the cities.