“…This paper suggests a simple method to derive default rates (DR) of loan portfolios from the time series of nonperforming loans (NPL). The NPL ratio (i.e., the ratio of NPLs to total loans in the portfolio) is a standard measure of loan quality widely used in research analyzing performance of banking sectors and their customers (e.g., Meeker and Gray, 1987;Lízal and Svejnar, 2002;Hasan and Wall, 2004;Podpiera, 2006;Mendoza and Terrones, 2008;Aman and Miyazaki, 2009;Festić et al, 2009;Čihák and Schaeck, 2010;Whalen, 2010;Jin et al, 2011). The well-known problem of this measure is the mechanistic dependence of its values on the rate of growth of the loan portfolio, which often forbids cross-sectional and inter-temporal comparisons (Tornell and Westermann, 2002, p. 22;Coricelli et al, 2006).…”