We use a stylised model to analyse the Stability and Growth Pact for countr
ies that have formed the European Monetary Union (EMU). In our model, short
sighted governments fail to internalise the consequences of their debt poli
cies for the common inflation rate fully. Therefore, while governments have
no incentive to sign a stability pact in the absence of a monetary union,
they do so with monetary union to restrain this externality. With uncertain
ty, a monetary union combined with an appropriately designed pact will he s
trictly preferred to autonomy. With differences in initial conditions, conf
licts of interest arise. We study the Nash bargaining solution.