Study on the Operation Efficiency of Toll Roads in China from the Perspective of Scale Economy
Table 7
Parameter estimation results.
(I)
(II)
(III)
(IV)
(V)
(VI)
Pooled OLS
Panel GMM
Panel GMM
Toll
8.300
3.105
9.038
6.965
—
—
(3.60)
(3.17)
(2.50)
(3.27)
Exp_per_land
—
—
—
—
2.674
11.86
(1.82)
(3.14)
Toll_int
−7.471
−2.806
−8.325
−8.847
−5.895
−9.682
(−1.97)
(−1.65)
(−2.07)
(−1.87)
(−1.77)
(−2.44)
Urban
−0.0124
−0.00278
−0.0276
−0.00469
0.00141
−0.0467
(−2.58)
(−1.91)
(−1.91)
(−2.95)
(0.63)
(−2.94)
Eply
0.255
0.0536
0.242
0.0621
0.0487
0.157
(5.62)
(2.69)
(3.93)
(2.52)
(2.71)
(3.05)
Toll_Station
−1.583
0.659
−2.067
0.784
0.000752
−0.000854
(−3.53)
(4.14)
(−3.20)
(4.59)
(3.57)
(−1.27)
Ltc
0.108
0.0168
0.0482
−0.0134
0.0602
−0.0450
(2.35)
(1.00)
(0.44)
(−0.82)
(3.29)
(−0.48)
Ave_Salary
−0.112
−0.230
−0.761
−0.230
−0.165
−1.425
(−0.31)
(−2.04)
(−1.16)
(−1.32)
(−1.04)
(−1.80)
Hansen
—
—
1
1
0.999
1
AR
—
—
0.113
0.405
0.205
0.274
N
174
174
145
145
145
145
Note.Statistical significance at the 10% level; statistical significance at the 5% level; statistical significance at the 1% level. The t-statistics calculated with the standard error of heteroscedasticity are reported in brackets.
