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From | "Jain, Monica (HarvestPlus)" <M.Jain@cgiar.org> |
To | "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |
Subject | st: Not sure how to interpret -somersd- results |
Date | Wed, 2 Oct 2013 20:47:19 +0000 |
I am using -somersd- and I am unsure how to interpret the results to test stochastic dominance. I am using Stata 13 for Windows. I have a two year cross-section data on heights of children 3-5 years. I want to check if the distribution of heights z-score of children in 2006 first order stochastically dominates those in 1996. From previous threads on stochastic dominance, I saw that one could use Somers D statistic for it. I am using the following command where 2006 is year=1, haz is the height z-score: somersd year haz, cluster(district) and I get the following result: Somers' D with variable: year Transformation: Untransformed Valid observations: 627 Number of clusters: 4 Symmetric 95% CI (Std. Err. adjusted for 4 clusters in dist) ------------------------------------------------------------------------------ | Jackknife year | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- haz06 | .357832 .0434275 8.24 0.000 .2727157 .4429483 -------------+---------------------------------------------------------------- What I know is that the above result indicates that a randomly selected child in 2006 is 36% more likely to have a higher height z-score than a randomly selected child in 1996, than vice versa. But, what I do not know is how do I state this result in terms of stochastic dominance. Can I say that distribution of height z-scores in 2006 first order stochastically dominates the distribution of height z-scores in 1996? Alternatively, can I make any statement about stochastic dominance from the above result? If yes, what would it be? Monica Jain * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/