Table 4. The effect of academic freedom (AF) on innovation output (patent applications) with additional control variables.
| Model | (1) | (2) | (3) | (4) | (5) | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Dependent variable | Patent applicationst+2 (ln) | Patent applicationst+2 (ln) | Patent applicationst+2 (ln) | Patent applicationst+2 (ln) | Patent applicationst+2 (ln) | |||||
| Statistic | Coeff. | (SE) | Coeff. | (SE) | Coeff. | (SE) | Coeff. | (SE) | Coeff. | (SE) |
| Indepedent variables | ||||||||||
| AF (z) | 0.275 | (0.037)*** | ||||||||
| AF (IV: Democracyt-5, z) | 0.221 | (0.070)*** | ||||||||
| AF (IV: Democracy stockt-10, z) | 0.250 | (0.065)*** | ||||||||
| AF (IV: AFt-5, z) | 0.316 | (0.053)*** | ||||||||
| AF (IV: AF stockt-10, z) | 0.305 | (0.052)*** | ||||||||
| Control variables | ||||||||||
| GDP per capita | -0.005 | (0.004) | -0.004 | (0.004) | -0.004 | (0.004) | -0.005 | (0.005) | -0.007 | (0.005) |
| Population (ln) | 0.112 | (0.113) | 0.148 | (0.124) | 0.166 | (0.125) | 0.216 | (0.119)* | 0.301 | (0.125)* |
| Migration rate | 0.001 | (0.001)* | 0.001 | (0.001)* | 0.001 | (0.001)* | 0.001 | (0.001)* | 0.001 | (0.001)* |
| Year/country dummies | Yes | Yes | Yes | Yes | Yes | |||||
| Countries (observations) | 148 | (7,257) | 148 | (7,092) | 148 | (6,962) | 148 | (6,980) | 147 | (6,679) |
| R2 (R2 adjusted) | 0.870 | (0.866) | 0.870 | (0.866) | 0.870 | (0.866) | 0.871 | (0.867) | 0.871 | (0.867) |
Notes: The estimates in Model (1) are obtained from a pooled OLS regression. The estimates in Models (2)–(5) come from 2SLS regressions. All variables are described in Table 1. Robust standard errors in parentheses.
* p < 0.10
** p < 0.05
*** p < 0.01.