seminars and conferences for valuable comments and suggestions. We are also grateful to legisla-

Classic theories of electoral discipline (Barro 1973, Ferejohn 1986) hold that frequent accountability keeps politicians on their toes. We evaluate the e¤ects of the duration of legislative terms on the performance of legislators. Causal inference is made di ¢ cult by the potential endogeneity of the duration of terms, which varies markedly across countries. We exploit a natural experiment in the Argentine House of Representatives to overcome this identi\u85cation problem. Results for various objective measures of legislative output show that longer terms enhance legislative performance. We discuss and test possible explanations. Our results together with interviews with legislators suggest that the accountability logic is overcome by an investment logic.We use a second experiment in the Argentine Senate to determine whether our results are speci c to a particular chamber and a particular time. The results from the Senate reinforce the idea that longer terms enhance legislative productivity. JEL Classi\u85cation: H