THE RECENT experience of the United Kingdom, in which it was ultimately forced to leave the European Exchange Rate Mechanism (ERM), suggests that it may not be appropriate for an oil-producing and exporting economy to fix its nominal exchange rate against its major trading, and non-oil-producing, partners' currencies. This is likely to be the case for the UK, in particular, which is now experiencing declining oil production and a deterioration in its oil trade balance.In a recent paper in this journal, Harvie (1992a) suggested that, for this economy, a declining real exchange rate was necessary to improve the competitiveness of non-oil exports to offset the deteriorating oil trade balance. If the nominal exchange rate is fixed, vis-his its main trading partners' currencies, this implies that wages and prices would face the brunt of the adjustment, thereby requiring a more painful, and possibly more prolonged, adjustment of output and employment than would be the case with a flexible exchange rate.The objective of this paper is to explore further, from a primarily theoretical perspective, the macroeconomic implications arising for an oil-producing economy operating with either a fixed or flexible exchange rate system1to explore, in particular, which of these two extreme systems best offers insulatory properties, in the sense of reducing the volatility of adjustment of key macroeconomic variables arising primarily from oil-related shocks.The issue is explored by analyzing a theoretical framework, which emphasizes the long-run nature of the adjustment process. Such an emphasis is particularly pertinent in models which assume that economic agents possess rational expectations, where long-run equilibrium will have a major bearing upon the short-run adjustment process itself, However, due to the complexity of the model developed here, it is not possible to derive analytically unambiguous results, hence emphasis is placed upon deriving results through numerical simulation. The results derived The author is fram the