Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
| From | amir gahremanpour <gamirali@hotmail.com> |
| To | statalist <statalist@hsphsun2.harvard.edu> |
| Subject | st: regression with categorical predictors |
| Date | Tue, 30 Aug 2011 11:06:52 -0500 |
Hello everybody, First let me apologize if my question is very primitive, I am trying to self educate myself about regression with stata. When I have a categorical predictor with more than two levels , I am not sure if the p-values stata provides are adjusted for multiple comparison or are not? This example is from stata documentation , variable region has 4 levels , are the p-values adjusted for 3 comparisons to the base level? I do not think so ! thanks a lot use http://www.stata-press.com/data/r12/census9 (1980 Census data by state) . regress drate medage i.region [w=pop] (analytic weights assumed) (sum of wgt is 2.2591e+08) Source | SS df MS Number of obs = 50 -------------+------------------------------ F( 4, 45) = 37.21 Model | 4096.6093 4 1024.15232 Prob > F = 0.0000 Residual | 1238.40987 45 27.5202192 R-squared = 0.7679 -------------+------------------------------ Adj R-squared = 0.7472 Total | 5335.01916 49 108.877942 Root MSE = 5.246 ------------------------------------------------------------------------------ drate | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- medage | 4.283183 .5393329 7.94 0.000 3.196911 5.369455 | region | 2 | .3138738 2.456431 0.13 0.899 -4.633632 5.26138 3 | -1.438452 2.320244 -0.62 0.538 -6.111663 3.234758 4 | -10.90629 2.681349 -4.07 0.000 -16.30681 -5.505777 | _cons | -39.14727 17.23613 -2.27 0.028 -73.86262 -4.431915 ------------------------------------------------------------------------------ . * testing the joint significance of joint variable * * 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/