Reserve currencies and dollarization
The US Dollar, Euro, Japanese Yen, and British Pound are reserve currencies held by central banks worldwide. Many countries peg their currency to the dollar or allow dollar circulation alongside their own currency (dollarization), reducing exchange risk for trade. The dollar's dominance reflects US military and economic power. Floating currencies (not pegged) are used in developed economies; fixed pegs are more common in smaller or less stable economies seeking to reduce volatility.
Currency strength and trade competitiveness
A strong local currency makes imports cheaper and exports more expensive, potentially hurting manufacturers. A weak currency does the opposite. Central banks often target a moderate currency strength to balance inflation (cheap imports) against export competitiveness. Currency crises occur when confidence in a currency collapses, suddenly devaluing it and making debt repayment impossible if borrowed in foreign currency. This dynamic shapes global trade flows and geopolitical stability.