It's only when you're not in a monetary union, when you have separate states with separate currencies, that it makes sense to have capital controls.

But I personally prefer floating exchange rates and agreesive macroprudential and foreign reserve policy to guard against the real-economy effects of exchange-rate fluctuations, and against hot money flows causing balance-of-payments crises.

Interventionist fixed-exchange-rate policies, especially it they try to prop up the value of the domestic currency, are probably a major contributor to catastrophic macroeconomic crises.

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman