Mexico Ran Out of Dollars and the Contagion Reached Countries With Nothing in Common
The 1994 peso crisis showed that a currency peg funded by short term dollar debt fails suddenly, and that investors respond by selling everything in the same category.
The Setup
Mexico had pegged its currency within a band against the dollar, which anchored inflation expectations and made the country attractive to foreign capital.
The difficulty was the current account deficit, funded by portfolio inflows that could reverse. To reassure nervous investors, the government issued short term debt indexed to the dollar, which lowered borrowing costs by removing currency risk from the lender.
Removing currency risk from the lender does not remove it. It transfers it to the borrower, who now owes more in local terms precisely when the currency falls.
Why the Structure Was Fragile
| Feature | Effect |
|---|---|
| Currency peg | Requires reserves to defend |
| Current account deficit | Needs continuous inflows |
| Dollar indexed short term debt | Devaluation multiplies the burden |
| Short maturities | Constant refinancing required |
Each element was individually manageable. Together they created a structure where a loss of confidence became self fulfilling: investors declining to roll over short term debt forced reserve use, which reduced reserves, which justified the concern.
The Break
Political shocks during 1994 and rising interest rates abroad reduced the attractiveness of the inflows. Reserves fell as the peg was defended. An attempted controlled adjustment to the band was read as evidence the authorities could not hold it, and the currency fell sharply.
The dollar indexed debt then did what such debt does. The peso obligation rose with the devaluation while the capacity to pay fell, converting a currency problem into a solvency problem within weeks.
The Contagion
The striking feature was what happened elsewhere. Investors sold assets in countries with no meaningful economic connection to Mexico, purely because those countries belonged to the same broad category.
The mechanisms are recognisable. Funds facing redemptions sell what is liquid rather than what is impaired. Investors update their assessment of a whole asset class rather than one country. And leveraged positions elsewhere are unwound to meet losses.
This is why contagion follows investor portfolios rather than trade relationships, and it remains the case.
What the Response Established
A large international support package was assembled, unusually quickly and at unusual size. It stabilised the situation and repayment was ultimately completed ahead of schedule.
The support also opened a debate that has never closed. Rescuing a country whose policies created the fragility protects lenders who accepted the yield without pricing the risk, which encourages the same behaviour next time. That concern about moral hazard shaped how later crises were approached.
What Changed Afterwards
The durable lessons were about structure rather than about Mexico. Pegs combined with short term foreign currency borrowing are a recognised vulnerability. Reserve adequacy is measured against short term external obligations rather than against imports. And floating rates, while volatile, adjust gradually rather than breaking suddenly.
Many emerging economies moved toward floating currencies, longer maturities, and local currency borrowing over the following decades, and those changes are why later global shocks caused less damage than this one.
The Bottom Line
A currency peg funded by short term dollar linked debt works until confidence wavers and then fails abruptly, with the debt burden rising exactly as capacity to pay falls. The contagion that followed spread through investor portfolios rather than economic links, which is why unrelated countries were sold at the same time.