-------------------------------------------------------------------------------- log: C:\Documents and Settings\Patricia_Anderson\My Documents\ECON 20\In > Class\nov8.log log type: text opened on: 8 Nov 2002, 11:12:10 . use fringe . desc Contains data from fringe.dta obs: 616 vars: 39 13 Sep 2000 15:30 size: 58,520 (100.0% of memory free) ------------------------------------------------------------------------------- storage display value variable name type format label variable label ------------------------------------------------------------------------------- annearn float %9.0g annual earnings, $ hrearn float %9.0g hourly earnings, $ exper byte %9.0g years work experience age byte %9.0g age in years depends byte %9.0g number of dependents married byte %9.0g =1 if married tenure float %9.0g years with current employer educ byte %9.0g years schooling nrtheast byte %9.0g =1 if live in northeast nrthcen byte %9.0g =1 if live in north central south byte %9.0g =1 if live in south male byte %9.0g =1 if male white byte %9.0g =1 if white union byte %9.0g =1 if union member office byte %9.0g =1 if office worker annhrs float %9.0g annual hours worked ind1 byte %9.0g =1 if industry == 1 ind2 byte %9.0g =1 if industry == 2 ind3 byte %9.0g ind4 byte %9.0g ind5 byte %9.0g ind6 byte %9.0g ind7 byte %9.0g ind8 byte %9.0g ind9 byte %9.0g vacdays float %9.0g $ value of vac. days sicklve float %9.0g $ value of sick leave insur float %9.0g $ value of employee insur pension float %9.0g $ value of employee pension annbens float %9.0g vacdays+sicklve+insur+pension hrbens float %9.0g hourly benefits, $ annhrssq float %9.0g annhrs^2 beratio float %9.0g annbens/annearn lannhrs float %9.0g log(annhrs) tenuresq float %9.0g tenure^2 expersq int %9.0g exper^2 lannearn float %9.0g log(annearn) peratio float %9.0g pension/annearn vserat float %9.0g (vacdays+sicklve)/annearn ------------------------------------------------------------------------------- Sorted by: . **"true" model . reg pension tenure educ depends white male union Source | SS df MS Number of obs = 616 -------------+------------------------------ F( 6, 609) = 47.51 Model | 75160263.5 6 12526710.6 Prob > F = 0.0000 Residual | 160575084 609 263670.089 R-squared = 0.3188 -------------+------------------------------ Adj R-squared = 0.3121 Total | 235735348 615 383309.508 Root MSE = 513.49 ------------------------------------------------------------------------------ pension | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- tenure | 24.14396 2.806861 8.60 0.000 18.63166 29.65626 educ | 77.83139 7.850794 9.91 0.000 62.41347 93.2493 depends | 38.93005 15.01716 2.59 0.010 9.438338 68.42176 white | 119.9991 72.17666 1.66 0.097 -21.74629 261.7444 male | 253.0995 44.86538 5.64 0.000 164.9898 341.2091 union | 292.9461 47.17389 6.21 0.000 200.3029 385.5893 _cons | -920.8319 122.8273 -7.50 0.000 -1162.048 -679.6154 ------------------------------------------------------------------------------ . **rig an example with pension topcoded at $1000 . gen topcode=pension . replace topcode=1000 if pension>1000 (186 real changes made) . **do OLS on topcoded data . reg topcode tenure educ depends white male union Source | SS df MS Number of obs = 616 -------------+------------------------------ F( 6, 609) = 51.49 Model | 35666109.7 6 5944351.62 Prob > F = 0.0000 Residual | 70311699.5 609 115454.351 R-squared = 0.3365 -------------+------------------------------ Adj R-squared = 0.3300 Total | 105977809 615 172321.641 Root MSE = 339.79 ------------------------------------------------------------------------------ topcode | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- tenure | 16.30634 1.857358 8.78 0.000 12.65873 19.95394 educ | 49.80145 5.195033 9.59 0.000 39.5991 60.00381 depends | 23.03612 9.937168 2.32 0.021 3.520843 42.55139 white | 112.0054 47.76079 2.35 0.019 18.20954 205.8012 male | 161.8824 29.68835 5.45 0.000 103.5784 220.1864 union | 236.6902 31.21594 7.58 0.000 175.3863 297.9942 _cons | -543.2142 81.27738 -6.68 0.000 -702.8322 -383.5963 ------------------------------------------------------------------------------ . **do a tobit instead . tobit topcode tenure educ depends white male union, ul Tobit estimates Number of obs = 616 LR chi2(6) = 254.68 Prob > chi2 = 0.0000 Log likelihood = -3384.5232 Pseudo R2 = 0.0363 ------------------------------------------------------------------------------ topcode | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- tenure | 23.19745 2.667536 8.70 0.000 17.95878 28.43612 educ | 68.49951 7.349961 9.32 0.000 54.06521 82.9338 depends | 40.84112 14.01785 2.91 0.004 13.31202 68.37021 white | 148.0687 64.62494 2.29 0.022 21.15433 274.983 male | 226.6394 40.39707 5.61 0.000 147.3052 305.9736 union | 307.7625 44.03888 6.99 0.000 221.2763 394.2487 _cons | -850.9585 113.8798 -7.47 0.000 -1074.603 -627.3145 -------------+---------------------------------------------------------------- _se | 447.3556 16.31646 (Ancillary parameter) ------------------------------------------------------------------------------ Obs. summary: 430 uncensored observations 186 right-censored observations at topcode>=1000 . use injury no; data in memory would be lost r(4); . use injury, clear . reg lduration afchnge highearn afhigh variable lduration not found r(111); . reg ldurat afchnge highearn afhigh Source | SS df MS Number of obs = 7150 -------------+------------------------------ F( 3, 7146) = 38.34 Model | 193.919839 3 64.6399463 Prob > F = 0.0000 Residual | 12047.1903 7146 1.68586486 R-squared = 0.0158 -------------+------------------------------ Adj R-squared = 0.0154 Total | 12241.1101 7149 1.71228285 Root MSE = 1.2984 ------------------------------------------------------------------------------ ldurat | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- afchnge | .0236351 .0397008 0.60 0.552 -.0541902 .1014603 highearn | .2151955 .0433612 4.96 0.000 .1301948 .3001962 afhigh | .1883498 .062794 3.00 0.003 .065255 .3114445 _cons | 1.199336 .0271091 44.24 0.000 1.146194 1.252478 ------------------------------------------------------------------------------ . log close log: C:\Documents and Settings\Patricia_Anderson\My Documents\ECON 20\I > nClass\nov8.log log type: text closed on: 8 Nov 2002, 12:29:01 -------------------------------------------------------------------------------