"This paper studies the impact of the Brazilian Arranjos Productivos Locais (APL) policy, a cluster development policy, on small and medium enterprises' (SMEs) performance. Using firm-level data on SMEs for the years 2002-2009, this paper combines fixed effects with reweighting methods to estimate both the direct and the indirect causal effects of participating in the APL policy on employment growth, value of total exports, and likelihood of exporting. Our results show that APL policy generates a positive direct impact on the three outcomes of interest. They also show evidence of short-term negative spillovers effects on employment in the first year after the policy implementation and positive spillovers on export outcomes in the medium and long term. Thus, our findings highlight the importance of accounting for the timing and gestation periods of the effects on firm performances when assessing the impact of clusters policies."