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# st: logit and mfx for randomized experiments

 From "Daniel S." To Subject st: logit and mfx for randomized experiments Date Sun, 1 May 2011 03:18:32 +0000

```I have run an experiment using a 2x2 between-subjects design. My dependent variable (y) is a dummy (1= if the participant bought a product we were offering; 0= if she did not buy it). I'm using the following:

xi: logit y x1 x2 i.x1*x2

x1 is a dummy (e.g. 1= product had a green package, 0= blue package)x2 is a dummy (e.g. 1= product had discount, 0= no discount)

So, one person could have seen the product in 1 out 4 ways (green and discount, blue and discount, green and non-discount, and blue and non-discount).

Is it OK, to get the results using 'mfx' after running the logit command? This would mean, that using the mfx coefficients I can interpreter the main and interaction effects of my conditions. In my case, the main effect of x1 was significant, the main effect of x2 was non significant, and the interaction was significant.

1. What's the difference of using odd-ratios instead? What's the most acceptable way to present these results? (mfx, margeff, odd-ratios, inteff)2. Is it OK that the p-values of are smaller after computing the mfx, compared to the raw coefficients of the logit regression?

Thanks a lot

Daniel
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