This paper analyses the link between interest rates and economic performance in a sto-chastic endogeneous growth

framework. The theoritical background is an overlapping generation model with production externality and incomplete

financial diversification. We shaw, in this setting, that the growth rate of output is negatively correlated with the risk-free

interest rate. Then, we compare two different economic policies : a primary budjet deficit control and an interest rate

control. The later policy is more stabilizing than the former.