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From | Scott Merryman <scott.merryman@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: Just and Pope Production model-What are the commands? |
Date | Wed, 12 Jun 2013 10:13:11 -0500 |
The general form of the Just and Pope production function is the regress yield on a set of explanatory variables. Then regress the log of the squared residuals on the set of explanatory variables. And then use the predicted values from the second regression as weights in first regression. You might want to take a look at -sfpanel- by Federico Belotti, Silvio Daidone, Giuseppe Ilardi, and Vincenzo Atella (-ssc desc sfpanel-). Several of the models allow for explanatory variables for the inefficiency variance function and the idiosyncratic error variance function Scott On Sun, Jun 9, 2013 at 12:08 PM, Kelvin Mulungu <kelvin.statalist@gmail.com> wrote: > Sorry for the less informative question. > > The Just and Pope (Just, R. E and R. D. Pope (1978). Stochastic > Specification of Production Function and Economic Implications. > Journal of Econometrics, 7(1978): 67-76) model am applying follows > closely with that which was used in Cabas et al 2010 (Cabas, J., A. > Weersink, and E. Olale (2010). Crop yield response to economic, site > and climatic variables. Climatic Change, 101:599–616) or by Isik and > Devadoss (Isik, M., and S. Devadoss (2006). An Analysis of the Impact > of Climate Change on Crop Yields and Yield Variability. Applied > Economics, 38:835-844.). > > This production function allows the effect of an input or > environmental factor to have a different effect on yield and the > variability of yield as measured by the standard deviation. In the > second stage, it is the standard deviation of yield which is used as > the dependent variable to measure the effect on yield variability > while the first stage has just yield as the dependent. Am applying it > to a 31 year panel which is unbalanced. > > Thanks. > > On Sun, Jun 9, 2013 at 7:30 PM, Nick Cox <njcoxstata@gmail.com> wrote: >> will already know about the Just and Pope model, but 50 or 500 might >> be interested in estimating production functions. >> >> Statalist is not primarily a way to get personal help in public; it is >> about building a forum of questions and answers that may be useful to >> as many people as possible. >> >> In short, please add helpful references and/or links to maximise the >> information here. >> >> Nick >> njcoxstata@gmail.com >> >> On 9 June 2013 17:21, Kelvin Mulungu <kelvin.statalist@gmail.com> wrote: >>> >>> Am supposed to use both the linear and Cobb-Douglas forms of the Just >>> and Pope production function model to check influence of climate on >>> crop yields, but am not able to find the commands. My data is panel >>> and unbalanced. I would like to try both fixed and random effects. >>> >>> And also how to generate the dependent variable for the second stage, >>> that is the standard deviation of yield. >> * >> * 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/ > > > > -- > Kelvin > kelvin.statalist@gmaill.com > > * > * 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/ * * 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/