Currency substitution, dollarization (see English spelling differences) is the use of a foreign currency in parallel to or instead of the domestic currency. Currency substitution can be full or partial. Most, if not all, full currency substitution has taken place after a major economic crisis, for example, Ecuador and El Salvador in Latin America and Zimbabwe in Africa. Some small economies, for whom it is impractical to maintain an independent currency, use those of their larger neighbours; for example Liechtenstein uses the Swiss franc.