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From | Maarten buis <maartenbuis@yahoo.co.uk> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: Polynomial in Time in an Unbalanced Panel |
Date | Fri, 18 Jun 2010 07:55:39 -0700 (PDT) |
--- On Fri, 18/6/10, natasha agarwal wrote: > I tried > > egen t1=group(year) > gen t2=t1^2 > gen t3=t1^3 > > But am not sure if this is correct for an unbalanced > panel? The -egen- step sounds dangerous an un-necessary to me (regardless of whether this balanced or un-balanced panel data or cross sectional data). I would just substract some meaningfull timepoint from your year variable to make sure that 0 zero is located within the range of your data. Other than that it looks ok to me. -- Maarten -------------------------- Maarten L. Buis Institut fuer Soziologie Universitaet Tuebingen Wilhelmstrasse 36 72074 Tuebingen Germany http://www.maartenbuis.nl -------------------------- * * 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/