If the cost benefit of interest rate swaps would probably be arbitraged away in competitive markets, what other explanations present to explain the rapid development of the interest rate swap market?
All kinds of debt instruments are not always obtainable to all borrowers. Interest rate swaps can assist in market completeness. I.e. a borrower may employ a swap to get out of one kind of financing and to get a more desirable type of credit that is more suitable for its asset maturity structure.