In this paper the authors reconsider the transmission of shocks to government spending across these regimes within a standard New Keynesian model of a small open economy. Because of the stronger emphasis on intertemporal optimization, the New Keynesian framework requires a precise specification of fiscal and monetary policies, and their interaction, at both short and long horizons. The authors derive an analytical characterization of the transmission mechanism of expansionary spending policies under a peg, showing that the long-term real interest rate always rises in response to an increase in government spending if inflation rises initially. This response drives down private demand even though short-term real rates fall. As this need not be the case under floating exchange rates, the conventional wisdom needs to be qualified. Under plausible medium-term fiscal policies, government spending is not necessarily less expansionary under floating exchange rates.