The literature which examines the impact of school spending on students' subsequent earnings is bifurcated into state-level studies, which typically find strong effects, and school-level studies,which find little effect. Since most of the school-level studies examine young workers, one explanation for the discrepancy is that school inputs benefit workers only as they gain job experience. The paper tests the hypothesis by using both school-level (NLSY) and state-level data sources (Census and the Biennial Survey of Education). Both data-sets suggest that there is typically no significant age dependence. Thus other explanations of the discrepancy are likely to explain the differing results. JEL Codes: I21, I24 1 1. Introduction Education is arguably one of the best long term public investments available to a society. It is widely accepted that the private returns to an additional year of education are quite high, and that the social returns are also high. Such beliefs form the basis ...