Against all odds, the euro celebrated its 22nd birthday this year.
From the Eurozone's inception, it was understood that economic convergence among its member countries was a prerequisite for the survival and prospering of the single currency.
The 2012 Eurozone crisis was brought on by a divergence in labor costs between countries in the south (Greece, Italy, Spain) and those in the north (Germany, Netherlands, Austria), creating a two-speed club that became economically and politically unsustainable.
The extreme pessimism towards the euro ten years ago was in a large part fed by the belief that the economic adjustment to achieve labor cost convergence would be so painful for the high cost countries, that it would be easier for them to do so by simply exiting the Eurozone.
In this respect, the fact that the Eurozone has pulled off unit labor cost convergence without losing a member in the process is an accomplishment that the Eurozone is not given enough credit for.
The Eurozone still has many issues to address to ensure the long-term survival of the euro, but it has at least one less problem.