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From | "Alexander M. Jais" <jais@win.rwth-aachen.de> |
To | statalist@hsphsun2.harvard.edu |
Subject | Again the requrest: SIMULATION TO INTERPRET AND PRESENT LOGIT RESULTS without formatting - hopefully looks better |
Date | Thu, 01 Mar 2012 12:34:27 +0100 |
Dear Statalisters,For some reason I’ve a really hard time to figure out how I can graph my logistic regression model in Stata. I am aware of the explanation of Zellner (2009; Strategic Management Journal) and Tomz M, Wittenberg J, King G. 2001. CLARIFY: Software for interpreting and presenting statistical results, 2.0 ed. Harvard University: Cambridge, MA).
I ve the following issue:·My logistic regression has the following expression simplified: logit EquityMode Psychic Distance Means-Driven PsychDxMeansD
oDependent Variable_Equity Mode: Code 0 = for Non-Equity and Code 1 = Equity
oInteraction Variable_Psychic Distance: Construct based on 6 items with 7 point likert scale
oIndependent Variable_Means-Driven: : Construct based on 6 items with 7 point likert scale
oModeration_ PsychDxMeansD: Psychic Distance times Means-Driven · Question: * In general I want to graph figures 2 and 3 in Zellner 2009 (pls see link for source:http://faculty.fuqua.duke.edu/~charlesw/s591/Methods/c09_Bennet/SMJ_note_final.pdf).
How do I code the Interaction Variable and Independent Variable, which are NOT binary – the explanation in Zellner shows only the binary interaction term (see lines 3, 10, … in Do file below; based on Zellner 2009, also attached, see pages 21-23) ? * Why is X replaced = .01 (in line 7)? * Why is in line 8 all independent variables set to zero? Do I also need to do that? My current Do-Files looks like this: 1. set seed 99992. noisily estsimp logit EquityMode PsychicDistance Means-Driven PsychDxMeansD, nolog
3. foreach var in X Y0 Y1 Y0lb Y1lb Y0ub Y1ub dY dYlb dYub { 4.gen `var' = . 5. } 6. forvalues obs = 1(1)18 { 7. replace X = .01*(`obs'+1) in `obs' 8. setx 0 9. setx Means-Driven .01*(`obs'+1) 10. foreach as_lev in 0 1 { 11.setx PsychicDistance `as_lev' PsychDxMeansD `as_lev'*.01*(`obs'+1) 12.simqi, genpr(Y`as_lev'_tmp) prval(1) 13.sum Y`as_lev'_tmp, meanonly 14.replace Y`as_lev' = r(mean) in `obs' 15._pctile Y`as_lev'_tmp, p(2.5, 97.5) 16.replace Y`as_lev'lb = r(r1) in `obs' 17.replace Y`as_lev'ub = r(r2) in `obs' 18.} 19.gen dY_tmp = Y1_tmp - Y0_tmp 20.sum dY_tmp, meanonly 21.replace dY = r(mean) in `obs' 22._pctile dY_tmp, p(2.5,97.5) 23.replace dYlb = r(r1) in `obs' 24.replace dYub = r(r2) in `obs' 25.drop *_tmp 26. }27. twoway rbar Y0ub Y1lb X, mw msize(1) lcolor(gs0) fcolor(gs16)|| line Y0 X, color(gs0) || rspike Y1ub Y1lb X, color(gs0) lp(dot) || line Y1 X, color(gs0) || , yscale (r(0 1)) ylabel(0(.2)1) legend(off) xtitle("Means Driven") ytitle("Equity Mode") graphregion(fcolor(gs16))
MANY THANKS for advice highly appreciated! All the best, Alex * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/