Abstract
The regulatory and business need to expand the use of macroeconomic-scenario-based forecasting and stress testing in retail lending has led to a rapid expansion in the types and complexity of models being applied. As these models become more sophisticated and include lifecycle, credit quality, and macroeconomic effects, model specification errors become a common, but rarely identified feature of many of these models. This problem was discovered decades ago in demography with Age-Period-Cohort (APC) models, and we bring those insights to the retail lending context with a detailed discussion of the implications here. Although the APC literature proves that no universal, data-driven solution is possible, we propose a domain-specific solution that is appropriate to lending. This solution is demonstrated with an auto loan portfolio.
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References
Arellano M (2003). Panel Data Econometrics. Oxford University Press: New York.
Banerjee R and Canals-Cerdaá JJ (June 2012). Credit risk analysis of credit card portfolios under economic stress conditions. Technical report, Federal Reserve Bank of Philadelphia, Research Department.
Bellotti T and Crook J (2009). Credit scoring with macroeconomic variables using survival analysis. Journal of the Operational Research Society 60 (12): 1699–1707.
Berkowitz J (2000). A coherent framework for stress testing. Journal of Risk 2 (2): 1–11.
Breeden JL (May 17 2007). Modeling data with multiple time dimensions. Computational Statistics & Data Analysis 51 (9): 4761–4785.
Breeden JL (2008). Validation of stress testing models. In: Christodoulakis GA and Satchell S (eds). The Analytics of Risk Model Validation. Academic Press: San Diego, CA, pp 13–25.
Breeden JL (2009). Survey of retail loan portfolio stress testing. In: Rsch D and Scheule H (eds). Stress-testing for Financial Institutions—Applications, Regulations and Techniques. Risk books: London.
Breeden JL (2010). Testing retail lending models for missing cross-terms. Journal of Risk Model Validation 4 (4): 49–57.
Breeden JL (2011). Macroeconomic adverse selection: How consumer demand drives credit quality. In: Credit Scoring and Credit Control XII Conference, Edinburgh, Available in the online conference proceedings at http://www.business-school.ed.ac.uk/crc/conferences/conference-archive?a=46054.
Breeden JL and Thomas LC (2008). The relationship between default and economic cycle for retail portfolios across countries: Identifying the drivers of economic downturn. Journal of Risk Model Validation 2 (3): 11–44.
Breeden JL, Thomas LC and McDonald III J (2008). Stress testing retail loan portfolios with dual-time dynamics. Journal of Risk Model Validation 2 (2): 43–62.
Committee on the Global Financial System (April 2001). A survey of stress tests and current practice at major financial institutions. CGFS Publications No. 18, http://www.bis.org.
Cox DR and Oakes DO (1984). Analysis of Survival Data. Chapman and Hall: London.
Demyanyk Y and Van Hemert O (2011). Understanding the subprime mortgage crisis. Review of Financial Studies 24 (6): 1848–1880.
Efron B (2002). The two-way proportional hazards model. Journal of the Royal Statistical Society B 64 (4): 899–909.
Glenn ND (2005). Cohort Analysis. 2nd edn. Sage: London.
Hansen LP and Sargent TJ (2008). Robustness. Princeton University Press: Princeton, NJ.
Holford T (2005). Encyclopedia of Statistics in Behavioral Science. chapter Age-Period-Cohort Analysis. Wiley: Hoboken, NJ.
Hosmer Jr. DW and Lemeshow S (1999). Applied Survival Analysis: Regression Modeling of Time to Event Data. Wiley Series in Probability and Statistics: New York.
Hosmer Jr. DW and Lemeshow S (2000). Applied Logistic Regression. 2nd edn. Wiley Series in Probability and Statistics: New York.
Hsiao C (2003). Analysis of Panel Data. Cambridge University Press: Cambridge, UK.
Judge G, Griffiths WE, Hill RC, Ltkepohl H and Lee T-C (1985). The Theory and Practice of Econometrics. Wiley: Hoboken, NJ.
Kolb R (ed) (2010). Lessons from the Financial Crisis: Causes, Consequences, and Our Economic Future. Wiley: Hoboken, NJ.
Lily C and Hong LP (August 2004). FSAP Stress Testing: Singapore’s Experience. Monetory Authority of Singapore, Staff Paper Number 34, http://www.mas.gov.sg/~/media/resource/publications/staff_papers/StaffPaper%20Lily%2012Aug_rv1pwp.pdf.
Malik M and Thomas LC (2010). Modelling credit risk of portfolio of consumer loans. Journal of the Operational Research Society 61 (3): 411–420.
Mason WM and Fienberg S (1985). Cohort Analysis in Social Research: Beyond the Identification Problem. Springer: New York.
Perli R and Nayda WI (2004). Economic and regulatory capital allocation for revolving retail exposures. Journal of Banking and Finance 28 (4): 789–809.
Rösch D and Scheule H (2007). Stress-testing credit risk parameters: An application to retail loan portfolios. Journal of Risk Model Validation 1 (1): 55–75.
Therneau TM and Grambsch PM (2000). Modeling Survival Data: Extending the Cox Model. Springer-Verlag: New York.
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Breeden, J., Thomas, L. Solutions to specification errors in stress testing models. J Oper Res Soc 67, 830–840 (2016). https://doi.org/10.1057/jors.2015.97
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DOI: https://doi.org/10.1057/jors.2015.97