In discussing the pros and cons of monetary union among several European nations, some politicians have claimed that living standards in the countries concerned would first have to converge if monetary union is not to lead to economic chaos.
Conclusion
It is false to say that .
i.e. it's possible that living standards don't converge, the European nations form a monetary union, and economic chaos does not result.
Evidence
Within individual countries, you have living standards that don't converge, and economic chaos does not result.
Evaluate
The author disputes a cause/effect connection by pointing to a somewhat different instance in which that cause/effect connection didn't hold.
We could call the evidence a counterexample to a principle, except that there was never an explicit principle, just an implied one that .
We could call the evidence an analogy, because the author is pointing to individual nations' economies as a relevantly similar instance in which the claimed connection between divergent living standards and economic chaos does not hold.
Goal
Pick anything that matches, but it will likely either talk about the author providing a counterexample to the politicians' claim or bringing up an analogous situation in which the supposed cause/effect relationship did not hold.