------------------------------------------------------------------------------------------------------------------------------- log: c:\drive\econ272\econ771_april_1_2008.log log type: text opened on: 1 Apr 2008, 09:31:45 . use "C:\drive\econ276\zismall.dta", clear . ta births births | Freq. Percent Cum. ------------+----------------------------------- 0 | 1,162 28.70 28.70 1 | 558 13.78 42.48 2 | 455 11.24 53.72 3 | 402 9.93 63.65 4 | 382 9.43 73.08 5 | 297 7.34 80.41 6 | 239 5.90 86.32 7 | 180 4.45 90.76 8 | 134 3.31 94.07 9 | 103 2.54 96.62 10 | 75 1.85 98.47 11 | 32 0.79 99.26 12 | 19 0.47 99.73 13 | 6 0.15 99.88 14 | 2 0.05 99.93 15 | 2 0.05 99.98 17 | 1 0.02 100.00 ------------+----------------------------------- Total | 4,049 100.00 . tobit births ageyr educf city goodwat goodsan,ll(0) Tobit regression Number of obs = 4044 LR chi2(5) = 4117.62 Prob > chi2 = 0.0000 Log likelihood = -7014.9249 Pseudo R2 = 0.2269 ------------------------------------------------------------------------------ births | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- ageyr | .2825085 .0043723 64.61 0.000 .2739363 .2910807 educf | -.1603301 .0119162 -13.45 0.000 -.1836925 -.1369677 city | -.4034701 .120642 -3.34 0.001 -.639995 -.1669452 goodwat | .0238674 .1114081 0.21 0.830 -.194554 .2422888 goodsan | -.1921134 .1016556 -1.89 0.059 -.3914145 .0071876 _cons | -4.292217 .16827 -25.51 0.000 -4.622119 -3.962315 -------------+---------------------------------------------------------------- /sigma | 2.168632 .029305 2.111178 2.226086 ------------------------------------------------------------------------------ Obs. summary: 1160 left-censored observations at births<=0 2884 uncensored observations 0 right-censored observations . mfx Marginal effects after tobit y = Fitted values (predict) = 2.3511649 ------------------------------------------------------------------------------ variable | dy/dx Std. Err. z P>|z| [ 95% C.I. ] X ---------+-------------------------------------------------------------------- ageyr | .2825085 .00437 64.61 0.000 .273939 .291078 27.7995 educf | -.1603301 .01192 -13.45 0.000 -.183686 -.136975 6.09891 city*| -.4034701 .12064 -3.34 0.001 -.639924 -.167016 .346934 goodwat*| .0238674 .11141 0.21 0.830 -.194489 .242223 .462413 goodsan*| -.1921134 .10166 -1.89 0.059 -.391355 .007128 .538328 ------------------------------------------------------------------------------ (*) dy/dx is for discrete change of dummy variable from 0 to 1 . truncreg births ageyr educf city goodwat goodsan,ll(0) (note: 1160 obs. truncated) Fitting full model: Iteration 0: log likelihood = -5713.7441 Iteration 1: log likelihood = -5622.1323 Iteration 2: log likelihood = -5618.6442 Iteration 3: log likelihood = -5618.6422 Iteration 4: log likelihood = -5618.6422 Truncated regression Limit: lower = 0 Number of obs = 2884 upper = +inf Wald chi2(5) =2152.96 Log likelihood = -5618.6422 Prob > chi2 = 0.0000 ------------------------------------------------------------------------------ births | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- ageyr | .262151 .0063065 41.57 0.000 .2497904 .2745116 educf | -.1314884 .0151894 -8.66 0.000 -.161259 -.1017178 city | -.5710415 .1570311 -3.64 0.000 -.8788167 -.2632662 goodwat | -.105644 .1404902 -0.75 0.452 -.3809997 .1697118 goodsan | -.3455518 .1274091 -2.71 0.007 -.595269 -.0958346 _cons | -3.516396 .2460534 -14.29 0.000 -3.998652 -3.03414 -------------+---------------------------------------------------------------- /sigma | 2.150767 .0376341 57.15 0.000 2.077006 2.224528 ------------------------------------------------------------------------------ . gen birthdum=births>0 . ta birthdum birthdum | Freq. Percent Cum. ------------+----------------------------------- 0 | 1,162 28.70 28.70 1 | 2,887 71.30 100.00 ------------+----------------------------------- Total | 4,049 100.00 . probit birthdum ageyr educf city goodwat goodsan Iteration 0: log likelihood = -2423.5783 Iteration 1: log likelihood = -1542.2833 Iteration 2: log likelihood = -1385.9413 Iteration 3: log likelihood = -1364.339 Iteration 4: log likelihood = -1363.8968 Iteration 5: log likelihood = -1363.8966 Probit regression Number of obs = 4044 LR chi2(5) = 2119.36 Prob > chi2 = 0.0000 Log likelihood = -1363.8966 Pseudo R2 = 0.4372 ------------------------------------------------------------------------------ birthdum | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- ageyr | .1472592 .0048553 30.33 0.000 .137743 .1567754 educf | -.0888368 .0092038 -9.65 0.000 -.1068758 -.0707977 city | -.1087962 .0877896 -1.24 0.215 -.2808607 .0632683 goodwat | .0713767 .0838878 0.85 0.395 -.0930403 .2357937 goodsan | .0308367 .0772066 0.40 0.690 -.1204855 .1821588 _cons | -2.40503 .1364531 -17.63 0.000 -2.672474 -2.137587 ------------------------------------------------------------------------------ . di 7014.9249-5618.6422-1363.8966 32.3861 . di 2*(7014.9249-5618.6422-1363.8966) 64.7722 . di chi2tail(6,64.7) 4.967e-12 . log lcose lcose invalid r(198); . log close log: c:\drive\econ272\econ771_april_1_2008.log log type: text closed on: 1 Apr 2008, 10:38:27 -----------------------------------------------------------------------------------------------------------------------------