Estimating the Value of Implicit Government Guarantees to Thai Banks

The paper estimates the contingent liability of the Thai government to their banking system prior to the 1997 financial crisis by maximizing a likelihood function that utilizes the established result that deposit insurance can be modeled as a put option on the value of bank assets. The results show that the estimated value of the government guarantee was large and statistically greater than the premium banks paid for this guarantee, suggesting that guarantees provided a subsidy to Thai banks. Additionally, the estimates are able to identify weak banks before the crisis emerged. These results suggest that the estimated value of implicit deposit guarantees can serve as an early warning indicator of banking crises. The paper contrasts the option pricing results with traditional balance sheet indicators, and demonstrates that these alternative indicators are unable to identify weaknesses in the Thai banking systems before the crisis.