In practice, the interest rate sensitivity of depository institution (DI) net worth is measured in terms of maturity mismatches arising from nominal contracts in their financial portfolios. Academic studies also frequently invoke nominal contracting to explain a positive covariation observed between DI stock returns and bond returns. For a sample of thrifts reporting detailed financial data (1984–1992), this study estimates monthly changes in their financial portfolio values due to changes in interest rates. These portfolio value changes are found to be unimportant in explaining the thrifts' stock returns and are unable to account for a positive covariation between the stock returns and bond market returns. Potential weaknesses in the tests seem inadequate to explain the results. Explanations other than nominal contracting may warrant more consideration in relating DIs' net worth to interest rate changes.
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