This paper estimates the relationship between initial wage and return to experience. We use a Mincer-like wage model to non-parametrically estimate this relationship allowing for an unobservable individual permanent effect in wages and unobservable individual return to experience. The relationship between return to experience and unobservable individual ability is negative when conditioning on educational attainment, while the relationship between return to experience and educational attainment is positive. We link our findings to three main theories of wage growth, namely search, unobserved productivity and learning, and human capital. We devise several empirical tests in order to separate the theories. We find evidence in favor of the unobserved productivity and learning model and mixed evidence regarding the search model. We find no evidence in support of the human capital model. Copyright © 2013 John Wiley & Sons, Ltd.