ABSTRACT Using new econometric methods, we separately estimate average transaction costs for over 167,000 bonds from a 1‐year sample of all U.S. municipal bond trades. Municipal bond transaction costs decrease with trade size and do not depend significantly on trade frequency. Also, municipal bond trades are substantially more expensive than similar‐sized equity trades. We attribute these results to the lack of bond market price transparency. Additional cross‐sectional analyses show that bond trading costs increase with credit risk, instrument complexity, time to maturity, and time since issuance. Investors, and perhaps ultimately issuers, might benefit if issuers issued simpler bonds.

ABSTRACT Using a complete record of U.S. over‐the‐counter (OTC) secondary trades in corporate bonds, we estimate average transaction costs as a function of trade size for each bond that traded more than nine times between January 2003 and January 2005. We find that transaction costs decrease significantly with trade size. Highly rated bonds, recently issued bonds, and bonds close to maturity have lower transaction costs than do other bonds. Costs are lower for bonds with transparent trade prices, and they drop when the TRACE system starts to publicly disseminate their prices. The results suggest that public traders benefit significantly from price transparency.