Lee, C. F., Wang, K. L., and Liu, D. A. 2008. Credit Migration Matrix Conditioned on Macroeconomic Factors: Using Modified Credit Cycle Index and Credit Portfolio View Methods. NTU Management Review, 19 (1): 241-268
Cheng-Few Lee, Distinguished Professor, Department of Finance, Rutgers University and Graduate Institute of Finance, National Chiao Tung University
Keh-Luh Wang, Associate Professor, Graduate Institute of Finance, National Chiao Tung University
Da-Ann Liu, Assistant Manager, Risk Management Division, Taishin International Bank Co., Ltd
Abstract
The purpose of this study is to investigate the impact on credit migration matrix due to changes in business cycle, and calculate related default probabilities. Credit migration matrix plays a crucial role in many credit risk models. We modify Wilson (1997a, 1997b) and Kim (1999), using TCRI credit rating data and various macroeconomic variables from 1970 to 2004, to estimate the transition matrix conditional on economic status. AR (1)-GARCH (1,1) model is proposed to simulate the macroeconomic variable and adjust the unconditional credit migration probabilities. The major empirical results reveal that, Credit Cycle Index model is more consistent with the expected decline in default probabilities for the speculative firms when business is in expansion; and Portfolio View model can provide higher default probabilities during recession periods. In particular, lower rating firms exhibit higher volatility in default probabilities.
Keywords
credit migration matrix credit portfolio view credit cycle index