Table 4.
Estimation results of impacts of interaction terms on CCOE based on SDM.
| (1) | (2) | (3) | (4) | (5) | (6) | |
|---|---|---|---|---|---|---|
| Direct effect | ||||||
| ln(WDC) | 3.200* (1.915) | 1.891*** (0.466) | 1.452*** (0.461) | 1.228*** (0.461) | − 0.023 (0.060) | 3.343*** (0.649) |
| ln(Pop) | 4.485*** (1.459) | 2.739** (1.242) | 3.389*** (1.255) | 3.003** (1.280) | 3.487** (1.394) | 3.954*** (1.198) |
| ln(PGDP) | 3.955*** (1.192) | 2.848*** (1.097) | 3.107*** (1.163) | 3.394*** (1.185) | 3.643*** (1.349) | 3.303*** (1.006) |
| ln(ST) | 0.362*** (0.113) | 0.311** (0.123) | 0.437*** (0.108) | 0.455*** (0.130) | 0.367*** (0.116) | 0.256** (0.109) |
| ln(HPV) | 0.197** (0.087) | 0.005 (0.056) | 0.045 (0.066) | 0.349*** (0.126) | 0.150* (0.091) | 0.062 (0.059) |
| Airport | 0.068 (0.187) | − 0.288 (0.206) | − 0.134 (0.209) | 0.182 (0.180) | 0.100 (0.197) | − 0.327* (0.191) |
| ln(Ter) | − 1.785* (0.968) | − 0.535 (0.974) | − 0.700 (0.993) | − 1.218 (1.073) | − 1.740 (1.121) | − 0.890 (0.938) |
| ln(WDC)*ln(Pop) | − 0.215* (0.125) | |||||
| ln(WDC)*ln(PGDP) | − 0.180*** (0.042) | |||||
| ln(WDC)*ln(ST) | − 0.074*** (0.021) | |||||
| ln(WDC)*ln(HPV) | − 0.071** (0.032) | |||||
| ln(WDC)*Airport | − 0.118 (0.080) | |||||
| ln(WDC)*ln(Ter) | − 0.135*** (0.025) | |||||
| Indirect effect | ||||||
| ln(WDC) | 2.352 (4.230) | 1.947* (1.030) | 0.129 (1.031) | 0.341 (1.659) | 0.099 (0.118) | 4.489*** (1.379) |
| ln(Pop) | 1.553 (2.133) | 2.613 (1.719) | 2.019 (1.988) | 1.670 (2.140) | 1.470 (2.155) | 2.594 (1.599) |
| ln(PGDP) | 0.374 (1.389) | 0.783 (1.286) | 0.309 (1.544) | 1.154 (1.567) | 0.754 (1.507) | 0.247 (1.158) |
| ln(ST) | − 0.430*** (0.153) | − 0.634*** (0.111) | − 0.452*** (0.139) | − 0.552*** (0.150) | − 0.392** (0.169) | − 0.608*** (0.115) |
| ln(HPV) | − 0.136 (0.188) | − 0.050 (0.183) | − 0.009 (0.223) | − 0.109 (0.308) | − 0.186 (0.226) | − 0.097 (0.161) |
| Airport | − 0.848 (1.162) | − 1.284 (1.364) | − 0.868 (1.368) | − 0.759 (1.211) | − 0.950 (1.279) | − 1.535 (1.187) |
| ln(Ter) | − 0.375 (1.211) | 0.058 (1.304) | − 0.638 (1.526) | − 1.128 (1.503) | − 0.520 (1.400) | 0.592 (1.166) |
| ln(WDC)*ln(Pop) | − 0.146 (0.276) | |||||
| ln(WDC)*ln(PGDP) | − 0.169* (0.093) | |||||
| ln(WDC)*ln(ST) | − 0.000 (0.048) | |||||
| ln(WDC)*ln(HPV) | − 0.015 (0.109) | |||||
| ln(WDC)*Airport | − 0.031 (0.209) | |||||
| ln(WDC)*ln(Ter) | − 0.172*** (0.054) | |||||
| Spatial rho | 0.440*** (0.093) | 0.340*** (0.061) | 0.477*** (0.090) | 0.410*** (0.091) | 0.449*** (0.083) | 0.284*** (0.060) |
| City-fixed effect | Yes | Yes | Yes | Yes | Yes | Yes |
| Obs | 240 | 240 | 240 | 240 | 240 | 240 |
| R-squared | 0.814 | 0.800 | 0.816 | 0.812 | 0.828 | 0.785 |
*p < 0.10, **p < 0.05, ***p < 0.01; the values in parentheses are standard errors.