ABSTRACT
It is always difficult to assess the optimality of a common currency in multiple state economies. The traditional optimal currency union literature offers the rationale for the adoption of a single currency but it does not provide specific indicators or values to assess how near a single currency may be to optimality. In our chapter we calculate and propose an overall index of the macroeconomic integration in a currency area, as well as several sub-indices. We have calculated such metrics for the eurozone and we have observed that internal asymmetries (1) grew from the very launch of the euro in 1999; (2) have worsened in the Global Financial Crisis’ years, particularly as regards competitiveness across member states; and (3) have diminished from 2014 to 2017 but remained stagnated since then and thus very far from the pre-crisis levels. Finally, we have calculated the same metrics for the USA and compare them with those of the eurozone. As shown in the paper, macroeconomic asymmetries within the USA did exacerbate before and during the 2008–2009 crisis’ years but are much more moderate and have already returned to pre-crisis levels.
