All proposals should therefore be measured against the yardstick of whether they strengthen the sustainability of the international financial system. Sustainability, a term that was originally coined in ecology, defines a development which does not seek short-term success to the detriment of long-term success.
The latest example is the Whitsun package of economic measures in 1998. The other main point of criticism of fixed-exchange-rate regimes is that a flexible exchange rate is necessary to shield the economy from external shocks. The same argument is used against participation in a monetary union.