The global market for currencies and finance influences the performance of all economies. The conditions in that market increasingly appear as exogenous variables of decisive importance. The macroeconomic equilibria of individual economies have to be related to the level and movements of interest rates determined in it and to the exchange rates established there between the leading currencies.
The external constraint is increasingly taking the form of the need for each country and economic region to be in overall balance, in terms of financial assets and liabilities, with respect to the rest of the world.