5.5.1 Model diagnostics

Various diagnostics related to instrument variable modeling are under development and testing, and will soon be available. This includes standard test estimators for endogeneity, correlation and overidentification. Until then, the modeling can be tested in the following ways:

• Run regression with and without instrumentation, and compare the result: regress vs. ivregress

• Use the correlate command to check for correlation between selected variables

• Study residuals a.o. through the ivregress-predict command