Benchmark interest rates when the government is risky

Since the Global Financial Crisis, rates on interest rate swaps have fallen below maturity matched U.S. Treasury rates across different maturities. Swap rates represent future un- collateralized borrowing between banks. Treasuries should be expensive and produce yields that are lower than those of maturity matched swap rates, as they are deemed to have supe- rior liquidity and to be safe, so this is a surprising development. We show, by no-arbitrage, that the U.S. sovereign default risk explains the negative swap spreads over Treasuries. This view is supported by a quantitative equilibrium model that jointly accounts for macroeco- nomic fundamentals and the term structures of interest and U.S. credit default swap rates. We account for interbank credit risk, liquidity effects, and cost of collateralization in the model. Thus, the sovereign risk explanation complements others based on frictions such as balance sheet constraints, convenience yield, and hedging demand.