Does Market Transparency Matter? a Case Study

We analyse a change in the degree of transparency of MTS, the electronic inter-dealer market for Italian Government bonds, namely the July 1997 move to the anonymity of quotes. Our evidence supports the hypothesis that a decrease in transparency makes liquidity traders worse-off, whereas large/informed traders find it less costly to execute block trades. The evidence is also consistent with the �waiting game� hypothesis of Foster and Viswanathan (1996): under anonymity, traders tend to delay their trades in an attempt to acquire information through the order flow. From a public welfare perspective, our results indicate that the move to anonymity has been accompanied by an increase in market liquidity and by a reduction in volatility, a phenomenon that is also partly explained by the growth in Italy�s prospects for early participation in the EMU. The speed of information aggregation on MTS increases, as shown by an improvement of the MTS lead over the futures market. In a European perspective, the current organisation and performance of MTS place the market in a competitive position with respect to other sovereign bond markets and may contribute to their integration under the single currency.