Asymmetric exchange rates and unofficial exchange rate interventions: The case of South Korea

Applying Milton Friedman's 'plucking' model of output fluctuations, we investigate the behavior of the Korean won/dollar exchange rate using a state-space model with Markov switching, which incorporates both symmetric and asymmetric shocks. We find that the Korean won/US dollar exchange rate rarely falls below its trend, but is plucked upward from time to time by transitory shocks. This asymmetry suggests that the monetary authority unofficially intervenes in the foreign exchange market to support its own target level from below. Further evidence from changes in reserve assets indirectly supports our finding.