Indeed, despite the early successes, virtually all the Latin American exchange-rate pegs proved unsustainable and collapsed in a disorderly way. Exchange-rate over-valuation, imperfect credibility of both monetary and fiscal policy, and short-duration external debt all contributed to a high incidence of costly speculative attacks and financial crises in Latin America during the 1990s and into the new millennium.
As already noted, Mexico was compelled to devalue in 1994. Brazil was forced from its peg in 1999, and Argentina (its currency board notwithstanding) in 2002. If not fixed exchange rates, then what? Ecuador and El Salvador have pursued strategies of official dollarization, the replacement of the local currency by the U.S. dollar as legal tender. (Panama has been dollarized for many years.)