Because poor, marginal lands were exempted from the annual land tax, and the Qing court rewarded officials who could induce people to expand cultivated land. Therefore the Viceroy of Chuan-Hu, Cai Yurong, observed that “there is an abundance of cultivated land in Szechwan, but there are not enough people to cultivate it,”[2] the throne decreed that “those who were willing to settle in Szechwan were to be tax-exempt for a period of five years and that any local official who could attract three hundred immigrants would be promoted immediately. (See 湖廣填四川 [zh])
Spence, Jonathan D. (2002), "The K'ang-hsi Reign", in Peterson, Willard J. (ed.), Cambridge History of China, Vol. 9, Part 1: The Ch'ing Dynasty to 1800, Cambridge: Cambridge University Press, pp. 120–182, ISBN0521243343.
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