A common currency could mitigate some of these adverse effects of a floating exchange rate system. From a purely economic point of view, a set of countries should opt for a common currency if the cost of losing national autonomy in monetary policy is mitigated by the benefits of a currency union. While it is difficult to quantify these costs and benefits, the OCA literature offers some guidelines to compare them. The benefits of a currency union increase and/or the costs decrease with (i) greater flexibility in wages and prices among the countries of the union, (ii) greater mobility of factors of production (labor and capital) across countries, (iii) more symmetric shocks across countries, (iv) more openness among the economies within the union, and (iv) larger share of trade among the countries of the region.