Study on the Operation Efficiency of Toll Roads in China from the Perspective of Scale Economy
Table 4
Parameter estimation results.
(I)
(II)
(III)
(IV)
(V)
(VI)
Pooled OLS
Panel GMM
Toll
6.678
0.888
6.851
5.725
1.858
6.591
(3.92)
(1.28)
(3.04)
(2.79)
(1.95)
(3.78)
Urban
−0.0138
−0.000636
−0.00912
−0.00724
−0.00414
−0.0118
(−3.01)
(−0.42)
(−2.13)
(−1.91)
(−2.83)
(−2.38)
Unemploy
−0.144
−0.0368
−0.00992
−0.239
−0.0483
−0.0401
(−2.39)
(−2.15)
(−0.17)
(−3.77)
(−4.19)
(−0.61)
Eply
0.192
0.0378
0.144
0.151
0.0308
0.159
(3.77)
(1.76)
(2.37)
(3.47)
(1.66)
(4.09)
Toll_Station
−1.642
0.618
−1.407
−2.887
0.442
−2.009
(−4.02)
(4.76)
(−4.08)
(−2.68)
(0.68)
(−2.05)
Ltc
0.161
0.117
−0.00765
0.207
0.116
−0.00746
(4.76)
(6.71)
(−0.27)
(6.03)
(8.68)
(−0.34)
Ave_Salary
0.203
−0.0534
0.668
0.518
−0.214
0.940
(0.77)
(−0.34)
(2.22)
(1.32)
(−2.41)
(2.18)
_cons
0.372
0.245
0.459
−0.177
0.660
0.376
(0.56)
(0.89)
(0.78)
(−0.21)
(3.75)
(0.55)
Hansen
—
—
—
1
1
1
AR
—
—
—
0.126
0.131
0.797
N
174
174
174
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.
