Table 3. Baseline DID regression results of total effects.
| Patents | Patents weighted by citation (W_Citation) | |||||
|---|---|---|---|---|---|---|
| OLS | DID | OLS | DID | |||
| (1) | (2) | (3) | (4) | (5) | (6) | |
| HSR | 1.203*** | 0.438*** | 0.431*** | 1.153*** | 0.375*** | 0.371*** |
| (0.0850) | (0.0439) | (0.0445) | (0.0875) | (0.0442) | (0.0450) | |
| ln(GDP) | 0.980*** | -0.00827 | 1.049*** | -0.00396 | ||
| (0.0254) | (0.0482) | (0.0263) | (0.0519) | |||
| ln(Pop) | -0.301*** | 0.362*** | -0.321*** | 0.305*** | ||
| (0.0400) | (0.0925) | (0.0418) | (0.0940) | |||
| ln(Temperature) | 0.460*** | 0.0929 | 0.503*** | 0.0428 | ||
| (0.0805) | (0.294) | (0.0851) | (0.318) | |||
| ln(PM2.5) | -0.118*** | -0.224*** | -0.107** | -0.24*** | ||
| (0.0416) | (0.0641) | (0.0439) | (0.07) | |||
| County fixed effects | No | Yes | Yes | No | Yes | Yes |
| Province-Year fixed effects | No | Yes | Yes | No | Yes | Yes |
| Number of counties/firms | - | 1,986 | 1,972 | - | 1,986 | 1,972 |
| R2 | 0.569 | 0.869 | 0.869 | 0.562 | 0.852 | 0.853 |
| Observation | 25,675 | 25,818 | 25,636 | 25,675 | 25,818 | 25,636 |
Notes: *, **, *** refers to the statistical significance at 10%, 5%, and 1%, respectively. The standard errors are reported in parentheses and clustered at county level.