# Computer Exercises Econometrics

Pages: 19 (4874 words) Published: September 27, 2010
Computer Exercises

C1.2
Use the data in BWGHT.RAW to answer this question.

. summ

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

(i) How many women are in the sample, and how many report
smoking during pregnancy?

Total number of women=1,388

. summ if cigs>0

Number of women who reported smoking during pregnancy=1,388-1177=212

(ii)What is the average number of cigarettes smoked per day?

. sum cigs

Average number of cigarettes smoked per day=2.087176

Is the average a good measure of the “typical” women in this case? Explain.

No, the average is not a good measure of the “typical” women in this case as when women are pregnant they tend to smoke less or not at all to protect their baby and enhance its development.

(iii) Among women who smoked during pregnancy, what is the average number of cigarettes smoked per day?

Average number of cigarettes smoked per day=13.62
[(1388x2.08)/212]

How does this compare to with your answer from part (ii), and why? It has increased significantly as the women who didn’t smoke during pregnancy would have brought the average down.

(iv) Find the average of fatheduc in the sample.

Average of fatheduc=13.18624

Why are only 1,192 observations used to compute this average?

There are only 1,192 observations as there was only 1,192 men available to provide the information or only 1,192 had an education.

(v) Report the average family income and its standard deviation in dollars.

Average family income=\$29,026.66
Standard deviation of family income=\$18,739.28

This standard deviation shows rather wide variation in incomes per family. [The minimum is \$500 and the maximum is \$65,000.]

C2.2
The data set in CEOSAL2.RAW contains information on chief executive officers for U.S. corporations. The variable salary is annual compensation, in thousands of dollars, and ceoten is prior number of years as company CEO.

. summ

Variable | Obs Mean Std. Dev. Min Max
-------------+----------------------------------------------------------------------------------- salary | 177 865.8644 587.5893 100 5299 age | 177 56.42938 8.42189 33 86 college | 177 .9717514 .1661523 0 1 grad | 177 .5310734 .5004492 0 1 comten | 177 22.50282 12.29473 2 58 -------------+----------------------------------------------------------------------------------- ceoten |...