Methods to identify inter-carrier telephone calls in a telephone system that are being mis-routed in such a way as to violate existing regulatory tariffs and/or established inter-carrier contracts. The common name for this manipulation is "arbitrage", and the intent of the perpetrators is to take advantage of lower rates associated with the delivery of telephone traffic via other routes. Through the processes of collecting call detail records and their correlation in representative embodiments, various call "legs" associated with the same call can be identified, and a more accurate "compound" call record can be made that incorporates call routing information obtained from the individual call legs. A statistical analysis can then be performed to more clearly illuminate any arbitrage.