The optimality of a gulf currency union: Commonalities and idiosyncrasies

A high degree of shared national elements that drive the bulk of observed output volatility between countries is generally seen as a necessary prerequisite for the formation of a successful monetary union. This is because countries in a monetary union accept a one-size-fits all, resigning regions to policies that are based on some aggregate macroeconomic target rather than a country-specific one. For this reason, the cost of monetary union membership depends on the incidence of asymmetric (nation-specific) shocks rather than symmetric, or common shocks. This criteria is examined for the Gulf Cooperation Council (GCC) countries, who reaffirmed plans for the implementation of a single currency. This paper quantifies, using structural factor models with common factor restrictions, changes in output synchronisation, the importance of common factor or idiosyncratic shocks between the regions, and the synchronisation of these shocks across the GCC as well as the implications for GCC-wide macroeconomic policy at short-to-medium term horizons. Despite current difficulties in fulfilling the convergence criteria goals to monetary union, the results show the synchronisation of output growth fluctuations between economies of the GCC to have increased over the past 25 years. This paper also finds that a fairly sizeable proportion of output fluctuations in business cycle frequencies are driven by a common component that, to some degree, reflects U.S. monetary policy and U.S. demand shocks as well as changes in crude oil prices.