What Is a Peg to the Dollar?

Why Countries "Peg" Their Currency to the Dollar

yuan peg to the dollar
China loosely pegs its currency, the yuan, to the dollar. Credit: PhotoAlto/James Hardy

Definition: A dollar peg is when a country maintains its currency's value at a fixed exchange rate to the U.S. dollar. The country's central bank controls the value of its currency so that it rises and falls along with the dollar. The dollar's value fluctuates because it’s on a floating exchange rate

There are at least 66 countries that either peg their currency to the dollar or use the dollar as their own legal tender.

The dollar is so popular because it's the world's reserve currency. World leaders gave it that status at the 1944 Bretton Woods Agreement.

The runner up is the euro. Twenty-five countries peg their currency to it. The 17 eurozone members use it as their currency. 

How Does a Dollar Peg Work?

A dollar peg uses a fixed exchange rate. That means the country's central bank promises it will give you a fixed amount of its currency in return for a U.S. dollar. To maintain this peg, the country must have lots of dollars on hand. That's why most of the countries that peg their currencies to the dollar have a lot of exports to the United States. Their companies receive lots of dollar payments. They exchange the dollars for local currency to pay their workers and domestic suppliers.

Central banks usually use the dollars to purchase U.S. Treasurys. They do this to receive interest on their dollar holdings.

If they need to raise cash to pay their companies, it’s easy to sell Treasurys on the secondary market.

A country's central bank will monitor its currency exchange rate relative to the dollar's value. If the currency falls below the peg, it needs to raise its value and lower the dollar's value. It does this by selling Treasurys on the secondary market.

That gives the bank cash to purchase local currency. By adding to the supply of Treasurys, their value drops, along with the value of the dollar. Reducing the supply of local currency raising its value. The peg is restored.  

Keeping the currencies equal is difficult, since the dollar's value changes constantly. That's why some countries peg their currency's value to a dollar range instead of the exact number.

Example

China uses a fixed exchange rate. That's because it prefers to keep its currency low to make its exports more competitive. In fact, every country tries to do this, but few have China's ability to keep it fixed. For more, see Currency Wars.

China's currency power comes from its exports to America. The exports are mostly consumer electronics, clothing and machinery. In addition, many United States-based companies send raw materials to Chinese factories for cheap assembly. The finished goods become imports when they are shipped back to the United States. For more, see U.S. Trade Deficit With China.

Chinese companies receive American dollars as payment for their exports. They deposit the dollars into their banks in exchange for yuan to pay their workers. Banks send the dollars to China's central bank, which stockpiles them in its foreign currency reserves.

This reduces the supply of dollars available for trade. That puts upward pressure on the dollar. For more, see How Does China Influence the U.S. Dollar?

China's central bank also uses the dollars to purchase U.S. Treasurys. It needs to invest its dollar stockpile into something safe that also gives a return, and there's nothing safer than Treasurys. China knows this will further strengthen the dollar and lower the yuan's value. For more, see U.S. Debt to China

Why Do Countries Peg Their Currency to the Dollar?

The U.S. dollar's status as the world's reserve currency makes many countries want to peg to it. One reason is because most financial transactions and international trade is done in U.S. dollars. Countries that are heavily reliant on their financial sector peg their currencies to the dollar.

Examples of these trade-reliant countries are Hong Kong, Malaysia and Singapore.

Other countries that export a lot to the United States peg their currencies to the dollar to maintain competitive pricing. They try to keep the value of their currency lower than the dollar. This gives them a comparative advantage by making their exports to America cheaper.  

Japan doesn't exactly peg the yen to the dollar. Its approach is similar to China. It tries to keep the yen low compared to the dollar because it exports so much to the United States. Like China, it receives a lot of dollars in return. As a result, the Bank of Japan is the largest purchaser of U.S. Treasurys. For more, see Who Owns the U.S. Debt?

Other countries, like the oil-exporting nations in the Gulf Cooperation Council, must peg their currency to the dollar because oil is sold in dollars. As a result, they have large amounts of dollars in their sovereign wealth funds. These petrodollars are often invested in U.S. businesses to earn a greater return. For example, Abu Dhabi invested petrodollars in Citigroup to prevent its bankruptcy in 2008. 

Countries that do a lot of trading with China will also peg their currency to the dollar. That’s because they want their exports to be competitive with the Chinese market. They want their export prices to always be aligned with the Chinese yuan. Pegging their currency to the dollar accomplishes that.