There's stuff here I've never heard about.
Can you explain how OLS can estimate "causal effects" please?
Nick
[email protected]
Lijun Song
> As a beginner at Stata, I am confused about the psmatch2.
>
> Suppose I am interested in the causal effect of college (a 1-0
> treatment indicator) on income. I also assume that race, sex, and
> family background (such as Mother and Father's SEI) will
> influence the
> treatment assignment. I also could not deny that race,sex, and family
> background also influence the outcome of interests, income directly.
>
> Then, after regressing income on college, I arrive at an estimated
> coffecient. After that, I use "psmatch2 college race sex masei pasei".
> I think the causal effect estimated by OLS estimator should be higher
> than those by Propensity Score Matching right?
>
> But my results show that the causal effect estimated by OLS
> is smaller
> than these by Propensity Score Matching. Why?
>
> In addition, the causal effect estimated by OLS is ATT or ATE?
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/