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From |
"Nick Cox" <n.j.cox@durham.ac.uk> |

To |
<statalist@hsphsun2.harvard.edu> |

Subject |
st: RE: RE: XTLSDVC and R-squared |

Date |
Mon, 14 Apr 2008 18:01:51 +0100 |

A small refinement here: use -summarize, meanonly- in each instance here. In this example the saving will be trivial, but it's a good habit to get into. There is more at SJ-7-3 st0135 . . . . . . . . . . . Stata tip 50: Efficient use of summarize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. J. Cox Q3/07 SJ 7(3):438--439 (no commands) tip on using the meanonly option of summarize to more quickly determine the mean and other statistics of a large dataset Rodrigo Alfaro A. I think that you could report within R2 from the LDV+FE model. It seems to me that you panel is large in T, is it unbalanced? Bruno (2005) -the author of -xtlsdvc- reports simulations on the effect of unbalancedness. You need the arithmetic (A), and harmonic (H) averages. You could check his results on the paper and use the following code to compute the statistics using your data. qui { * Arellano-Bond dataset webuse abdata sum year gen time = year - r(min) + 1 * Getting the max time for firm bysort id: egen tmax=max(time) * Leaving only the result in last period replace tmax=. if time!=tmax gen double inv_tmax = 1/tmax sum tmax local A = r(mean) sum inv_tmax local H = 1/r(mean) local R = `A'/`H' } di in ye "Arithmetic =" `A' ", Harmonic=" `H' ", H/A=" `R' Bruno, G. (2005) "Approximating the bias of LSDV estimator for dynamic unbalanced panel data models" Economic Letters, 87: 361-6 -----Original Message----- Rodrigo, The coefficients in the LSD+FE are very close to the ones from -xtlsdvc-, a little different but very close. I have around 11,000 observations, so it takes close to 2 hours to run one model in xtlsdvc, but I can get a good quick sense of what the results will be with just and the LSD+FE. * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**References**:**st: XTLSDVC and R-squared***From:*"Jon O'Brien" <Jon.OBrien@ucd.ie>

**st: RE: XTLSDVC and R-squared***From:*"Rodrigo Alfaro A." <ralfaro@bcentral.cl>

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