Lloyd Dixon, a RAND economist, recently testified before the U.S. House of Representatives Committee on Public Works and Transportation regarding transaction costs involved in the cleanup of hazardous waste sites. Transaction costs are those that do not contribute directly to the understanding or cleanup of a site. Insurer transaction costs, he stated, were high: 88% of the total expenditures. They were split between coverage disputes and defense of policyholders. For large firms who were potentially responsible parties (PRPs), transaction costs, primarily for legal counsel, averaged 21% of total outlays, but decreased proportionally as cleanup progressed. These costs varied across sites, averaging 7% of the total where only a single PRP was involved and 39% where multiple PRPs were. Dixon concluded his testimony by suggesting that these facts may not tell much about the future, since insurance coverage issues are still unresolved, PRPs involved in cleanup may yet sue non-participating PRPs, and insurers may pursue their reinsurers as their own losses mount.