Does Airport Preferential Policy Aggravate the Competition of Aviation Hubs in Central and Western China? Based on the Investigation of 78 Airports

Table 5

Direct, indirect, and total effects of the SDM.

Spatial effect	Area	lntra	lncm	lnrf
Direct effect	The whole country	0.0292	0.0224	−0.0235
		(−3.34)	(−4.38)	(−3.22)
	Eastern region	0.0157	0.0113	0.0135
		(−1.7)	(−1.83)	(−1.53)
	Central and western	0.0571	0.007	−0.0579
		(−3.77)	(−0.85)	(−5.07)
Indirect effect/spatial spillover effect	The whole country	0.0318	−0.0059	−0.025
		(−1.26)	(−0.41)	(−1.07)
	Eastern region	0.0176	0.0092	0.0001
		(−1.07)	(−0.65)	(0.00)
	Central and western	0.1356	−0.0685	−0.1131
		(−2.35)	(−2.93)	(−1.90)
Total effect	The whole country	0.0610	0.0165	−0.0485
		(−2.12)	(−0.97)	(−1.81)
	Eastern region	0.0333	0.0206	0.0136
		(−1.65)	(−1.16)	(−0.65)
	Central and western	0.1927	−0.0615	−0.1710
		(−3.09)	(−2.27)	(−2.63)

t statistics in parentheses. , , and .