Dear all,

I want to explore the effects of X on Y. Considering X might be an exogenous variable, I perform both the OLS and IV regression.

OLS gets significant results (coefficient = 0.3, std.err=0.058,p=0.000), while the IV regression gets insignificant results (coefficient=0.2, std.err=0.648, p>0.1). Then I would think that there may be no causal effects of X on Y according to IV.

However, when I do the endogeneity test following by ivregress command, the test is insignificant, indicating no exogenous variable. So How to interpret the results? Should I think OLS gets the real causal effects due to there is no exogenous variable or should take the results of IV that there are no causal effects between X and Y?

Thanks for your help.