Table 4.
Sample Means of Variables Used in the Bootstrapped Truncated Regression Model.
| Variable | Definition | Mean | VIF |
|---|---|---|---|
| SO2 | Sulfur dioxide (10,000 tons) | 0.645 | 8.252 |
| NOx | Nitrogen oxides (10,000 tons) | 0.685 | 9.051 |
| S&D | Smoke and dust (10,000 tons) | 0.467 | 4.760 |
| ERev | Entropy index of revenue diversification. | 0.971 | 1.334 |
| RoadI | Road intensity, distance of roads (km) divided by the area (10,000 km2) of provinces | 9.151 | 3.465 |
| RailI | Railroad intensity, distance of railroads (km) divided by the area (10,000 km2) of provinces | 0.248 | 2.794 |
| DE | 1 if the province is in the east region; 0 otherwise | 0.419 | 4.422 |
| DC | 1 if the province is in the central region; 0 otherwise | 0.452 | 3.825 |
| Year13 | 1 if the year is 2013; 0 otherwise | 0.250 | 1.514 |
| Year14 | 1 if the year is 2014; 0 otherwise | 0.250 | 1.852 |
| Year15 | 1 if the year is 2015; 0 otherwise | 0.250 | 1.839 |
Note: All nominal variables are deflated by the GDP deflator with 2011 as the base year. VIF, variance inflation factor.