| Equation (4.1) | Equation (4.2) | Equation (4.3) | |
| Constant | −1.492 | −1.782 | −2.075 |
| (0.523) | (0.520) | (0.573) | |
| Exchange rate | −0.001 | ||
| (0.000) | |||
| Trade openness (% GDP) | 0.030 | 0.030 | 0.038 |
| (0.006) | (0.007) | (0.007) | |
| FDI (% of GDP) | 0.088 | 0.065 | 0.061 |
| (0.029) | (0.027) | (0.030) | |
| Inflation | −0.003 | −0.003 | |
| (0.002) | (0.002) | ||
| Tariff rate, all products (%) | 0.041 | 0.038 | 0.038 |
| (0.019) | (0.020) | (0.021) | |
| AID (% of GDP) | 0.010 | 0.010 | 0.010 |
| (0.002) | (0.002) | (0.002) | |
| Observation | 77 | 77 | 79 |
| R-squared | 0.64 | 0.61 | 0.61 |