Table 2.
SP Impact Survey: naive and instrumental variables (IV) models for effect of SP on CHEa and OOPb health expenditures control for all covariates in Table 1. Robust standard errors in parentheses. OLS ordinary least squares, 2SLS two-stage least squares, 2SRI two-stage residual inclusion, ME marginal effect
| CHE | OOP spending | |||
|---|---|---|---|---|
| Outpatient | Hospitalization | Medicines | ||
| Naive estimatesc | ||||
| OLS | −195.2*** (34.4) | −261.2*** (60.3) | −71.0** (28.2) | |
| Probit (ME) | −0.030** (0.004) | |||
| IV estimatesd | ||||
| 2SLS | −447.1*** (71.8) | −450.3*** (125.2) | −110.9* (58.9) | |
| Bivariate Probit (ME) | −0.046** (0.007) | |||
| Correlation coefficient (ρ) | 0.109** (0.042) | |||
| 2SRI (ME) | −0.047** (0.007) | |||
| Residuals (ME) | 0.031** (0.008) | |||
* Significant at 10%, ** significant at 5%, *** significant at 1%
aCHE defined as OOP spending greater than 30% of survival consumption (over US$2 per day)
bAnnualized OOP spending measured in Mexican pesos of 2006
cNaive models assume exogeneity of the treatment variable
dIV models deal with endogeneity of selection into SP