EXERCISE 2 - ANSWER

We might think that those who have more years of education would choose to postpone the age of first sex, as they are more likely to be aware of various STD's and other risks. Investigate this hypothesis, by regressing sexage on educ. Is there a statistically significant relationship between age of first sex and level of education?

By typing
 

reg sexage educ

      Source |       SS       df       MS              Number of obs =    2005
-------------+------------------------------           F(  1,  2003) =    8.87
       Model |  72.6737934     1  72.6737934           Prob > F      =  0.0029
    Residual |   16405.025  2003  8.19022714           R-squared     =  0.0044
-------------+------------------------------           Adj R-squared =  0.0039
       Total |  16477.6988  2004  8.22240457           Root MSE      =  2.8619

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      sexage |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
        educ |    .055436   .0186102     2.98   0.003     .0189386    .0919333
       _cons |   17.95426    .177452   101.18   0.000     17.60625    18.30227
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We see that education explains less than 1% of the variation in age of first sex. In addition, this effect is small (age of first sex goes up by 0.05 of one year for each additional year of education) and significant (which we can see from the P>|t| = 0.003).
 

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