http://etd.lib.clemson.edu/documents/1306872757/Carnot_clemson_0050M_11171.pdf
[FONT="] As you can see, the estimated decrease in income at the age of 23 for each day of marijuana use as a teen and each day of cigarette use as a teen are $70.38 and $90.16 respectively, while each day of alcohol use as a 16 year old is estimated to increase future earnings by an average of $233.69. The coefficients for the level of alcohol consumption and the level of cigarette consumption are both significantly different from zero at a 99% confidence level, while the coefficient for the number of days of marijuana use is only found to be significant at a 90% confidence level. Still, this regression is consistent with the previous results in this paper that suggested alcohol use as a teen was expected to increase future income, while both marijuana and cigarette use as a 16 year old was found to decrease earnings in young adults. [/FONT]