汇率
A "currency board" enables governments to manage their external credibility problems and discipline their central banks by “tying their hands” with binding arrangements. A currency board combines three elements: an exchange rate that is fixed to another, “anchor currency”; automatic convertibility or the right to exchange domestic currency at this fixed rate whenever desired; and a long-term commitment to the system. A currency board system can ultimately be credible only if central bank holds official foreign exchange reserves sufficient to at least cover the entire monetary base. Exchange rate movements cannot buffer external shocks.