ln(earnings) = 7.059 + 0.147 * educ + 0.49 * experience + 0.201 * female
               (1.35)  (0.008)        (0.007)             (0.36)

R2 = 0.179; n = 1801

ln(earnings) = 6.703 + 0.151 * educ
               (0.182) (0.12)

R2 = 0.153; n = 1801