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From | "L.M.A. Mulotte" <L.Mulotte@uvt.nl> |
To | "'statalist@hsphsun2.harvard.edu'" <statalist@hsphsun2.harvard.edu> |
Subject | st: graphing interaction when direct effect is curvilinear |
Date | Wed, 12 Sep 2012 07:48:08 +0000 |
Dear readers I would like to graph interaction effects for an OLS when the direct effect is curvilinear. Specifically, I would like to graph the impact of Z on the curvilinear relationship between Y and X, for Z being held at means plus 1 one SD and at means minus 1 SD, and all other variables being held constant. I would be very grateful for any advice. Here is an example showing my problem use http://www.stata-press.com/data/r11/nlswork gen age2 = age*age gen age2_x_birth_yr= age2*birth_yr (this is the interaction between age and birth_yr) regress ln_wage age age2 birth_yr age_x_birth_yr age2_x_birth_yr grade i.race i.south The graph I would like to draw has the following characteristics - Vertical axis is ln_wage - Horizontal axis is age - one inverted-U shaped curve for birth_yr held at means plus one SD, keeping other variables constant. - one inverted-U shaped curve curve for birth_yr held at means minus one SD, keeping other variables constant. Thank you very much for your consideration. Louis ***************************************************************************** Louis Mulotte Organization and Strategy Tilburg University School of Economics and Management PO Box 90153 - 5000 LE - Tilburg - The Netherlands Room: K1123 / Email: l.mulotte@tilburguniversity.edu / Phone: +31 13 466 8706 ***************************************************************************** * * 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/