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From |
irene@theicct.org |

To |
statalist@hsphsun2.harvard.edu |

Subject |
st: Question regarding deterministic frontier analysis |

Date |
Wed, 28 Nov 2012 11:00:00 -0800 (PST) |

Hi, I am new to STATA 12 and am trying to model a deterministic cost frontier using a set of panel data. However, I know that STATA's "frontier" function is for stochastic frontier. Is it possible to model with just a u (technical inefficiency) term rather than also a v (random noise) term (i.e. all of the variation is captured as technical inefficiency)? So far, I've tried frontier lnvar1 lnvar2 lnvar3, dist(hnormal) cost Iteration 0: log likelihood = 16.566731 Iteration 1: log likelihood = 16.600926 Iteration 2: log likelihood = 16.730963 Iteration 3: log likelihood = 16.747086 Iteration 4: log likelihood = 16.750521 (not concave) Iteration 5: log likelihood = 16.755428 Iteration 6: log likelihood = 16.755633 (not concave) Iteration 44: log likelihood = 16.757851 (not concave) Iteration 45: log likelihood = 16.757851 (not concave) Iteration 46: log likelihood = 16.757851 (not concave) Iteration 47: log likelihood = 16.757851 (not concave) Iteration 48: log likelihood = 16.757851 Stoc. frontier normal/half-normal model Number of obs = 15 Wald chi2(2) = 3672.72 Log likelihood = 16.757851 Prob > chi2 = 0.0000 ------------------------------------------------------------------------------ lnvar1 | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- lnvar2 | .87537 .0853459 10.26 0.000 .7080951 1.042645 lnvar3 | .1496319 .0825894 1.81 0.070 -.0122404 .3115042 _cons | -5.472008 2.328865 -2.35 0.019 -10.0365 -.9075169 -------------+---------------------------------------------------------------- /lnsig2v | -5.072258 .3681989 -13.78 0.000 -5.793915 -4.350602 /lnsig2u | -17.64313 37500.48 -0.00 1.000 -73517.24 73481.95 -------------+---------------------------------------------------------------- sigma_v | .0791723 .0145756 .0551909 .113574 sigma_u | .0001475 2.765992 0 . sigma2 | .0062683 .0023471 .0016681 .0108685 lambda | .0018632 2.767901 -5.423124 5.42685 ------------------------------------------------------------------------------ Likelihood-ratio test of sigma_u=0: chibar2(01) = 0.00 Prob>=chibar2 = 1.000 Thank you, Irene * * 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/

**Follow-Ups**:**Re: st: Question regarding deterministic frontier analysis***From:*Scott Merryman <scott.merryman@gmail.com>

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