have similar goals or preferences if one wish to pursue a certain minimum of co-
operation of economic policy. Looking upon the historical evidence such
uniqueness in preferences between the EU member states is most likely not fully
at place at present.
Industrial structure: If the industrial structures are very different between
members of a union, as pointed out by Kenen (1969), changes in the composition
of demand will influence the members differently and thereby create asymmetric
shocks. The more alike the countries are with regard to structure the less the risk
and magnitude of such an asymmetric shock will become. Regarding the overall
distribution on main sectors, agriculture is still relatively important in Greece,
Portugal, and Ireland, although this difference from the other member states is
diminishing rather rapidly. At the same time the industrial structures in
manufacturing between countries is also not uniform. Taken together these
differences would though hardly make the emerging of an asymmetrical shock
very likely. Rather it would be the limited mobility of goods and services that
would account for such country specific shocks although its likelihood is difficult
to measure precisely. Despite the establishment of the Internal Market, the
relationship between most firms and their customers is still at least to a certain
degree characterised by stickiness, and therefore it takes time for the firms to
change their outlets.
Openness of the economy: The openness of the economy reflects the degree of
integration of the goods markets. If these are highly integrated through trade the
benefits of a common currency are relatively large. Members of the union, who are
closely connected to each other through export and import, will experience
significant aggregate demand spillovers. Even if the members are hit by an
asymmetric shock, this will only to a limited degree lead to an asymmetric
development in output and employment within the union. As shown later, the
intra-EU trade, measured as a share of GDP, has increased quite a bit during the
past 40 years. Regarding openness, the EU countries therefore seem to have
become more open during the period of enhanced integration.