about the effectiveness of sterilised intervention and the channels through which current account imbalances influence exchange rates. Evidence of a substantial risk premium, however, is not required to verify that current account imbalances can have a substantial influence on exchange rates, since wealth effects are not the only channel through which current account imbalances can exert their influence A portfolio balance model of Germany is set out and estimated by Obstfeld (1983) and the effects of sterilised and non-sterilised foreign reserve sales are studied through dynamic perfect-foresight simulations of the empirical model. A sample of monthly data from January 1975 to October 1981 is used estimate the model The study makes inquiry into whether imperfect substitutability between foreign and domestic bonds is sufficient to allow the Bundesbank to attain independent internal and external goals over the short run of about a month. The model’s verdictis that the Bundesbank has little if any power to influence the exchange rate over that time span without altering current or expected future money-market cond