Can Highway Networks Promote Productivity? Evidence from China

Table 9

Result of instrumental variable.

Variables	OLS	Second stage	First stage
	TFP	TFP	Traveltime
Traveltime	−0.2018	−1.1570
	(−10.7397)	(−88.1026)
Traveltime_res		0.6659
		(48.2075)
Elevation_2000			0.0313
			(104.7437)
Elevation_2001			0.0334
			(111.5930)
Elevation_2002			0.0411
			(146.2454)
Elevation_2003			0.0372
			(132.5134)
Elevation_2004			0.0323
			(146.5773)
Elevation_2005			0.0319
			(144.0628)
Elevation_2006			0.0331
			(161.1244)
Elevation_2007			0.0329
			(160.3346)
Elevation_2008			0.0331
			(142.6269)
Elevation_2009			0.0336
			(133.7109)
Elevation_2010			0.0346
			(182.0807)
Elevation_2011			0.0315
			(163.6914)
Elevation_2012			0.0335
			(147.4631)
Elevation_2013			0.0306
			(173.6674)
Age	0.0653	−0.0576	0.0019
	(36.9506)	(−71.3241)	(15.2815)
Scale	0.2264	0.2089	0.0023
	(167.7992)	(481.1905)	(36.8894)
Export	0.0095	−0.0340	0.0380
	(3.7152)	(−19.0374)	(172.9643)
Own state	−0.0985	−0.6504	0.0228
	(−14.6627)	(−1.8e + 02)	(33.5935)
GDP	0.1921	0.0870	−0.0112
	(28.3932)	(55.2847)	(−41.2738)
R&D	0.0223	−0.0221	0.0116
	(16.4775)	(−39.4607)	(140.7426)
POP	0.0085	−0.0085	0.0027
	(8.3017)	(−15.9969)	(31.0327)
FDI	0.0216	−0.0088	−0.0034
	(17.9286)	(−11.9593)	(−18.1358)
Railway	−0.0538	−0.0778	−0.0223
	(−10.5808)	(−1.1e + 02)	(−1.9e + 02)
Constant	1.2244	12.1491	9.2524
	(6.4738)	(96.9508)	(5.4e + 03)
Firm fixed effect	Yes	Yes	Yes
Time fixed effect	Yes	Yes	Yes
N	3,027,046	3,027,046	3,027,046
R-squared	0.0932		0.2970
Kleibergen-Paap rk Wald F			23.188

Note. Standard errors are stated in parentheses below point estimates. 1%, 5%, and 10% significance levels.