We explore the use of expert witnesses in arbitration proceedings by analyzing public procurement contract disputes in Italy. Balancing cost with accuracy, participants to a contract select arbitration when speedy dispute resolution is valued highly. Arbitration mechanisms tend to give arbitrators discretion in how to proceed. Consequently, principal-agent problems can arise. Using an IV approach, we show that the use of an expert witness causes a slowing down of the case resolution, without having an effect on the outcome of the dispute nor resolving uncertainty as measured by unanimous decisions by the panel of arbitrators
