The paper is organized as follows. Section II estimates
the semi-log quadratic speci® cation of the earnings function
and assesses its performance in approximating actual
earnings pro® les at diOEerent stages of career. Section III
introduces alternative speci® cations of earnings function
and assesses their performances relative to the semi-log
quadratic function. Section IV provides estimates of the
measures of out-of-sample prediction errors to ascertain
the relative performance of alternative speci® cations.
Concluding remarks are made in Section V.