log using l:\2007_2008\econ571\solutions\5a, replace t use l:\2007_2008\econ571\stata_data\bwght regress bwght cigs regress bwght cigs faminc correlate cigs faminc log close clear . . regress bwght cigs Source | SS df MS Number of obs = 1388 -------------+------------------------------ F( 1, 1386) = 32.24 Model | 13060.4194 1 13060.4194 Prob > F = 0.0000 Residual | 561551.3 1386 405.159668 R-squared = 0.0227 -------------+------------------------------ Adj R-squared = 0.0220 Total | 574611.72 1387 414.283864 Root MSE = 20.129 ------------------------------------------------------------------------------ bwght | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- cigs | -.5137721 .0904909 -5.68 0.000 -.6912861 -.3362581 _cons | 119.7719 .5723407 209.27 0.000 118.6492 120.8946 ------------------------------------------------------------------------------ . . regress bwght cigs faminc Source | SS df MS Number of obs = 1388 -------------+------------------------------ F( 2, 1385) = 21.27 Model | 17126.2088 2 8563.10442 Prob > F = 0.0000 Residual | 557485.511 1385 402.516614 R-squared = 0.0298 -------------+------------------------------ Adj R-squared = 0.0284 Total | 574611.72 1387 414.283864 Root MSE = 20.063 ------------------------------------------------------------------------------ bwght | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- cigs | -.4634075 .0915768 -5.06 0.000 -.6430518 -.2837633 faminc | .0927647 .0291879 3.18 0.002 .0355075 .1500219 _cons | 116.9741 1.048984 111.51 0.000 114.9164 119.0319 ------------------------------------------------------------------------------ . . correlate cigs faminc (obs=1388) | cigs faminc -------------+------------------ cigs | 1.0000 faminc | -0.1730 1.0000 . summarize Variable | Obs Mean Std. Dev. Min Max -------------+-------------------------------------------------------- faminc | 1388 29.02666 18.73928 .5 65 cigtax | 1388 19.55295 7.795598 2 38 cigprice | 1388 130.559 10.24448 103.8 152.5 bwght | 1388 118.6996 20.35396 23 271 fatheduc | 1192 13.18624 2.745985 1 18 -------------+-------------------------------------------------------- motheduc | 1387 12.93583 2.376728 2 18 parity | 1388 1.632565 .8940273 1 6 male | 1388 .5208934 .4997433 0 1 white | 1388 .7845821 .4112601 0 1 cigs | 1388 2.087176 5.972688 0 50 -------------+-------------------------------------------------------- lbwght | 1388 4.760031 .1906622 3.135494 5.602119 bwghtlbs | 1388 7.418723 1.272123 1.4375 16.9375 packs | 1388 .1043588 .2986344 0 2.5 lfaminc | 1388 3.071271 .9180645 -.6931472 4.174387 . describe Contains data from l:\2007_2008\econ571\stata_data\bwght.dta obs: 1,388 vars: 14 3 Jun 1997 13:47 size: 55,520 (94.6% of memory free) ------------------------------------------------------------------------------- storage display value variable name type format label variable label ------------------------------------------------------------------------------- faminc float %9.0g 1988 family income, $1000s cigtax float %9.0g cig. tax in home state, 1988 cigprice float %9.0g cig. price in home state, 1988 bwght int %8.0g birth weight, ounces fatheduc byte %8.0g father's yrs of educ motheduc byte %8.0g mother's yrs of educ parity byte %8.0g birth order of child male byte %8.0g =1 if male child white byte %8.0g =1 if white cigs byte %8.0g cigs smked per day while preg lbwght float %9.0g log of bwght bwghtlbs float %9.0g birth weight, pounds packs float %9.0g packs smked per day while preg lfaminc float %9.0g log(faminc)