This paper produces evidence in support of the existence of common risk factors in the U.S. and UK interest rate swap markets. Using a multivariate smooth transition autoregression (STVAR) framework, we show that the dynamics of the U.S. and UK swap spreads are best described by a regime-switching model. We identify the existence of two distinct regimesWe would like to thank Robert Webb (the Editor) and a referee of this journal for very useful comments and suggestions. We have also benefited from the comments of Dick Van Dijk (who has provided us with nonlinear routines in Gauss), Mike Clements, Gary Koop, Chris Martin, Lucio Sarno, and Giorgio Valente. Any remaining errors are ours. *Correspondence author, Department of Economics, City University, Northampton Square, London EC1V OHB, UK; e-mail: c.milas@city.ac.uk
Received October 2002; Accepted April 2003
I Ilias Lekkos is in the Credit Risk Management Division at Halifax-Bank of Scotland Treasury Services in London, United Kingdom
I Costas Milas is a Senior Lecturer in the Department of Economics at City University in the United Kingdom
222Lekkos and Milas in U.S. and UK swap spreads; one is characterized by a "flat" term structure of U.S. interest rates and the other is characterized by an "upward" sloping U.S. term structure. In addition, we show that there exist significant asymmetries on the impact of the common risk factors on the U.S. and UK swap spreads. Shocks to UK oriented risk factors have a strong effect on the U.S. swap markets during the "flat" slope regime but a very limited effect otherwise. On the other hand, U.S. risk factors have a significant impact on the UK swap markets in both regimes.