A Transaction Level Study of the Effects of Central Bank Intervention of Exchange Rates

We study the effects of sterilized intervention operations executed on behalf of the Swiss National Bank (SNB) using tick-by-tick transaction data between 1985-95.We extend preliminary analysis conducted by Fischer and Zurlinden (1999) by matching these data with intra-day indicative exchange ate quotes and with news-wire reports of central banks ’activity. Via an event study analysis we find that intervention has important short-run effects on exchange ate returns and volatility. In particular, among various results, we find that intervention i) has a stronger impact when the SNB moves with-the-market and when its activity is concerted with that of other central banks, ii) is partially anticipated by the market and iii) temporarily reduces market liquidity.