Identifying the effects of central bank intervention

"Most intervention studies have been silent on the assumed structure of the economic system--implicitly imposing implausible assumptions--despite the fact that inference depends crucially on such issues. This paper proposes to identify the cross-effects of intervention with the level and volatility of exchange rates using the likely timing of intervention, macroeconomic announcements as instruments and the nonlinear structure of the intervention reaction function. Proper identification of the effects of intervention indicates that it is moderately effective in changing the levels of exchange rates but has no significant effect on volatility. The paper also illustrates that such inference depends on paying careful attention to seemingly innocuous identification assumptions"--Federal Reserve Bank of St. Louis web site.