Twin Crises

The term twin crises was popularized by economists Graciela Kaminsky and Carmen Reinhart in their 1999 American Economic Review paper "The Twin Crises: The Causes of Banking and Balance-of-Payments Problems." They documented that in many emerging-market episodes, problems in the banking sector and pressures on the exchange-rate peg are deeply interconnected, with banking-sector weakness typically preceding currency collapse, and the currency collapse in turn deepening the banking crisis.

The mechanics usually run in both directions. When banks hold large foreign-currency liabilities or lend to firms that do, a sharp depreciation balloons the domestic-currency value of those debts, triggering insolvency. Conversely, when authorities prop up failing banks with liquidity support or bailouts, the resulting monetary expansion and fiscal strain can erode confidence in the currency peg, inviting speculative attack. Financial liberalization without adequate prudential supervision, capital-account openness, and implicit government guarantees are common preconditions.

Kaminsky and Reinhart found that twin crises tend to produce deeper output losses and longer recoveries than either crisis type alone. Their early-warning work identified leading indicators such as overvalued real exchange rates, declining reserves, rising real interest rates, equity-price collapses, and credit booms.

Classic examples include:

• The 1994–95 Mexican "Tequila" crisis, in which the peso devaluation and the collapse of a heavily dollar-exposed banking system reinforced one another.
• The 1997–98 Asian financial crisis, where Thailand, Indonesia, and South Korea experienced simultaneous currency collapses and banking-sector failures tied to short-term foreign borrowing.
• Argentina in 2001–02, where the end of convertibility coincided with the corralito freeze on bank deposits.

The concept remains central to IMF surveillance and to debates on capital controls, macroprudential regulation, and the sequencing of financial reform. It also informs the broader literature on "sudden stops" (Calvo) and sovereign-bank "doom loops" later highlighted in the 2010–12 eurozone crisis.