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| From | Maarten Buis <maartenlbuis@gmail.com> |
| To | statalist@hsphsun2.harvard.edu |
| Subject | Re: st: OLS versus Ordered Probit |
| Date | Fri, 9 Dec 2011 12:44:05 +0100 |
On Fri, Dec 9, 2011 at 3:59 AM, Venkiteshwaran, Vinod wrote: > This question is not about stata per se but more of an econometrics query. Sounds to me more like a statistical question... > What are the strengths/drawbacks of using OLS, as opposed to ordered probit or logit, to estimate a model of ordered choices? That depends on the nature of the dependent variable. One potential problem with linear regression (linear regression is the model, OLS is only the method used to compute the coefficient) can be defining a meaningful scale for your dependent variable. Some variables are a coarsened version of a continuous variable others are truly ordered variables. In the former case you can often derive a more or less meaningful scale for your dependent variable, in the latter case that is usually impossible. Say you have a question in the form of a statement and the respondent can choose between 5 categories from strongly agree to strongly disagree, than assigning those categories the values 1 till 5 and using linear regression will assume that the distance between the 5 categories are all equal, which is usually problematic. Ordered model relax that assumption. Hope this helps, 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/