How long does it take for government decentralization to affect corruption?

Are countries with more decentralized fiscal and spending powers characterized by a lower level of corruption? Do changes in the degree of decentralization of such powers affect the level of corruption? If so, with which delay? This paper innovates on the previous literature, which relies mainly on cross sections of countries, by analyzing a pool of 24 countries for the time interval 1995–2007. The answer to both questions is positive and the estimated average delay is 3 years. The results appear robust to changes of the estimation techniques, of the indicators of corruption, of decentralization and of a variety of controlling factors.