the economic benefits of adopting the euro accrue to both the member states that join the euro area and to the euro area as a whole
detailed analysis and argumentation on this matter can be found for example in the commission's emu ten report of two thousand and eight
under the treaties all eu member states are obliged to join the euro area once they fulfil the necessary conditions
however denmark and the united kingdom have negotiated an opt-out clause that allows them to remain outside the euro area
if denmark and the united kingdom decide to apply for membership of the euro area they will be subject to the same convergence assessment as any other candidate as happened with other member states that have already joined the euro area
the commission would support their preparations fully including preparations for the actual cash changeover
sweden does not have an opt-out clause
for the time being sweden does not fulfil all the criteria for introducing the euro
in particular it is not a member of the exchange rate mechanism tool and some elements of its central bank legislation would have to be made compatible with euro area membership
nevertheless the commission considers that those member states not currently in a position to fulfil all convergence criteria for joining the euro should strive to meet these conditions
