What is the optimal number of currencies in the world? Common currencies affect trading costs and, thereby, the amounts of trade, output, and consumption. From the perspective of monetary policy, the adoption of another country's currency trades off the benefits of commitment to price stability...

Different beliefs about how fair social competition is and what determines income inequality, influence the redistributive policy chosen democratically in a society. But the composition of income in the first place depends on equilibrium tax policies. If a society believes that individual effort...