Currency boards also have downsides. In fixed exchange-rate systems, currency boards don’t allow the government to set their interest rates. That means economic conditions in a foreign country usually determine interest rates. By pegging the domestic currency to a foreign currency, the currency board imports much of that foreign country’s monetary policy.
When two countries are at different points in the business cycle, a currency board can create serious issues. For example, suppose the central bank raises interest rates to restrain inflation during an expansion in the foreign country. The currency board transmits that rate hike to the domestic economy, regardless of local conditions. If the country with a currency board is already in a recession, the rate hike could make it even worse.
In a crisis, a currency board can cause even more damage. If investors offload their local currency quickly and at the same time, interest rates can rise fast. That compromises the ability of banks to maintain legally required reserves and appropriate liquidity levels.
Such a banking crisis can get worse fast because currency boards cannot act as a lender of last resort. In the event of a banking panic, a currency board cannot lend money to banks in a meaningful way.