Research on World Food Production Efficiency and Environmental Sustainability Based on Entropy-DEA Model

Table 3

Indicator selection.

Input indicators	Output indicators
	Expected output	Unexpected output
Labor (million)	Grain yield (billions of tons)	Environmental pollution index
Agricultural land (percent of land area)
Agricultural irrigation (percent of total agricultural land)
Fertilizer consumption (kilograms per hectare of arable land)
Agricultural machinery (tractors per 100 Sq. km of arable land)