Table 2. Variable definition and summarized statistics.
| Variable | Scale | Description | Mean and standard deviation | ||
|---|---|---|---|---|---|
| Full Sample | With HSR | Without HSR | |||
| Panel A: Dependent variables | |||||
| Patent number (Total effect) | County level | Total number of invention patent applications by firms in each county-year | 67.83 | 284.63 | 13.08 |
| (747.7) | (1632.51) | (111.67) | |||
| W_Citation (Total effect) | County level | Total number of invention patent applications weighted by citation | 86.2 (889.03) | 526.03 (2329.04) | 15.93 (119.88) |
| Firm number (Extensive margin) | County level | Total number of firms with invention patent application in each county-year | 13.62 | 55.3 | 3.09 |
| (129.33) | (282.38) | (16.37) | |||
| Patent intensity (Intensive margin) | Firm level | Number of invention patent applications in each firm-year | 1.05 | 1.09 | 0.88 |
| (8.94) | (9.69) | (4.36) | |||
| Panel B: HSR status (Independent variables) | |||||
| HSR | County level | Dummy, 1 for county after operation of HSR, 0 otherwise | 0.062 | 0.305 | 0 |
| (0.24) | (0.461) | (0) | |||
| HSR | Firm level | Dummy, 1 for firm located in the county with HSR access, 0 otherwise | 0.51 | 0.627 | 0 |
| (0.5) | (0.484) | (0) | |||
| Panel C: Socio-economic outcomes and natural conditions (Control variables) | |||||
| GDP | County level | Gross Domestic Product (billion yuan) | 21.81 | 64.59 | 11.01 |
| (84.99) | (179.85) | (17.4) | |||
| Pop | County level | Number of permanent residents (thousand) | 615 | 1096.8 | 493.34 |
| (799.86) | (1527.47) | (372.6) | |||
| PM2.5 | County level | Annual surface of PM2.5 concentration (μg/m3) | 34.7 | 40.18 | 33.36 |
| (18.23) | (15.35) | (18.62) | |||
| Temperature | County level | Annual average temperature of the county (°C) | 13.73 | 15.76 | 13.23 |
| (5.51) | (4.72) | (5.57) | |||
| Obs | County level | Number of observations | 25,857 | 5,213 | 20,644 |
| Obs | Firm level | Number of observations | 1,537,488 | 1,249,485 | 288,003 |
Notes: Standard deviations are in parenthesis. The total effect and extensive margin of HSR impacts are measured at the county level, and the intensive margin of HSR impacts is measured at the firm level.