Table 7.
Comparing Experimental and Non-experimental Estimates
| Dependent variable | Coefficient estimate (s.e.) on programme indicator OLS (1) |
Coefficient estimate (s.e.) on normalized test score (2005–7) IV-2SLS [Experimental] (2) |
Coefficient estimate (s.e.) on normalized test score (2005–7) OLS [Non-experimental] (3) |
Hausman test p-value, H0:βIV = βOLS (columns 2, 3) (4) |
|---|---|---|---|---|
| Lack of autonomy index | −0.181** (0.077) | −0.872* (0.493) | −0.286*** (0.078) | 0.11 |
| Satisfaction with authority index | −0.239*** (0.061) | −1.149** (0.494) | −0.177*** (0.055) | < 0.01*** |
| Agree with ‘It is sometimes necessary to use violence in support of a just cause.’ (0–1) (vs. ‘The use of violence is never justified in politics.’) | 0.059** (0.029) | 0.285 (0.185) | −0.021 (0.018) | 0.04** |
| Ethnic identity is not ‘very important’ (0–1) | −0.033 (0.020) | −0.158 (0.105) | 0.001 (0.013) | 0.11 |
| Religious identity is not ‘very important’ (0–1) | 0.005 (0.006) | 0.023 (0.031) | −0.001 (0.005) | 0.43 |
| Democratic attitudes index | 0.023 (0.098) | 0.109 (0.436) | 0.344*** (0.060) | 0.52 |
| Days read a newspaper in last week (0 to 7) | 0.134* (0.074) | 0.644* (0.364) | 0.258*** (0.055) | 0.26 |
| Political knowledge index | 0.203** (0.085) | 0.975*** (0.325) | 0.464*** (0.045) | 0.08* |
| Perceived political efficacy index | 0.055 (0.066) | 0.265 (0.346) | −0.033 (0.050) | 0.31 |
| Participation in politics and civic affairs index | −0.038 (0.073) | −0.183 (0.363) | 0.017 (0.068) | 0.56 |
Notes
Each cell contains results from a separate regression. Significant at 90% (*), 95% (**), 99% (***) confidence.
Details on the mean effect analysis are in the text. Standard errors are clustered by school. The sample size is 1387 for all dependent variables.
In column (1), the outcome variable is regressed on the GSP (treatment) indicator, an indicator for student cohort, student age at time of the survey, educational attainment of each parent, and timing of the follow-up survey (coefficient estimates not shown). In column (2), the outcome variable is regressed on the same explanatory variables, except that the GSP indicator is replaced by the normalized test score (in 2005–7) across all subjects, and the test score is instrumented by the GSP indicator. In column (3), the normalized test score (in 2005–7) across all subjects is included as an explanatory variable but it is not instrumented, and the sample is restricted to the control group (sample size 664). Column (4) presents the Hausman test results (p-value) on the hypothesis that the coefficient estimates are equal across columns (2) and (3) for each dependent variable.