Empirical Evidence for UIP: Correlation between Interest Differentials and Depreciation Rates

Using the South Africa Case to Illustrate Long-Term UIP Implications

An economic theory proposes that the expected rate of a currency's depreciation is approximately equal to the difference between the home and foreign interest rates. To test this theory using historical data, researchers often examine the relationship between the actual rate of currency depreciation and the interest rate differential. What critical assumption is necessary to justify using the actual depreciation rate as a substitute for the expected depreciation rate in this empirical test?

An economist wants to use historical data to test a theory that links the expected change in a currency's value to the difference in interest rates between two countries. Since expectations cannot be directly observed, the economist must follow a logical process to create a testable hypothesis. Arrange the following statements into the correct logical sequence that transforms the initial theory into an empirically testable relationship.

Designing an Empirical Test for an Economic Theory

Applying Economic Theory to Real-World Data

Critiquing an Empirical Study

An economist observes that a country's actual currency depreciation rate over the last decade was consistently lower than its interest rate differential relative to a foreign country. This finding, on its own, is sufficient evidence to conclude that the underlying economic theory—which states that the expected rate of currency depreciation is approximately equal to the interest rate differential—must be incorrect.

Justifying an Empirical Test of an Economic Theory

An economist is building a model to empirically test a theory about international financial markets. The process involves a core theoretical relationship, a key long-run assumption, and a final testable hypothesis. Match each of these components to its correct description.

Evaluating Data Suitability for an Economic Test

An economic theory proposes that the expected rate of a currency's depreciation is determined by the difference between home and foreign interest rates. A second, related proposition is that, over the long run, these expectations are generally consistent with actual currency movements. If both of these propositions are true, what is the logical and empirically testable conclusion?