Exchange Rates and the Effectiveness of Actual and Oral Official Interventions: A Survey on Findings, Issues and Policy Implications

Monetary authorities of many open economies have been regularly intervening in foreign exchange markets for years to limit volatility in exchange rates and/or push exchange rates back to some desired level. Such interventions have taken the form of actual and oral official interventions. Review of studies investigating the effectiveness of interventions reveals one major issue, related to the assumption that interventions are mostly sterilized. This assumption might lead to unreliable results when changes in interest rates and interventions are both used as explanatory variables for exchange rates.One major consistent finding is that intervention has a significant but short-lasting effect on exchange rates. Studies have reached this conclusion by investigating whether intervention has been effective in turning around the exchange rate over the few days, weeks or months following intervention(s). Only a few studies have investigated and provided evidence that intervention has been effective in limiting long swings in exchange rates.Studies testing for the effectiveness of interventions specifically through the signaling channel also provide evidence on the importance of macroeconomic variables for exchange rates. The significance of official intervention and official communication for exchange rate movements combined with the importance of macroeconomic variables for exchange rates provide a role for official intervention and parity announcement to influence exchange rate movements and limit the magnitude of exchange rate swings.