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This study examines credit risk of non-financial companies and its impact on financial stability. It covers models, methodology, stress-testing, and conclusions from data analysis and validation. Results present probabilities of default at economy and sector levels for different time frames.
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Academy of Economic Studies Doctoral School of Finance and Banking Credit risk of non-financial companies in the context of financial stability Credit risk of non-financial companies in the context of financial stability MSc Student: Romulus Mircea Supervisor: Professor Moisă Altăr Bucharest, July 2007
Topics • Preliminary aspects • Credit risk models in practice • Methodology and input data • Results • Stress-testing • Conclusions
1. Preliminary aspects 1.1. Importance of credit risk assessment models: - Entities who buy and sell credit risk - Central authorities 1.2. Objectives: - Determinants of default for non-financial companies - Estimate probabilities of default - Evaluate risks to financial stability - Stress-testing Stakeholders Conclusions
2. Credit risk models in practice • Logit models are among the best alternatives to model credit risk of non-publicly traded companies • Currently used by central banks from euro-zone area, in order to determine eligible collateral for refinancing operations (OeNB, BUBA, BDE) • Ohlson (1980), Lennox (1999), Bernhardsen (2001), Bunn (2003) • Multivariate discriminant analysis: Beaver(1966), Altman(1968), Bardos(1998), BdF current methodology as an ECAI • Does not produce a probability of default directly • Rather restrictive assumptions on underlying explanatory variables
3. Methodology and input data • Methodology (1) • Default = 90 days past due bank loans obligations (Basel II) • Explanatory variables are financial ratios derived from firms’ financial statements
3. Methodology and input data • Methodology (2) • Variable selection filters • Ratios hypothesis tests using KS test • Monotony and linearity tests • Univariate accuracy tests • Multicolinearity • Model estimation • Bootstrapping Logit using a backward selection methodology on a 50:50 sample of defaulting to non-defaulting firms • Calibrate probabilities of default on the real portfolio • Model Validation • Economic performance measures: • ROC/AR, Hit rates, False alarm rates • Statistical performance measures: Hosmer Lemeshow test, Spiegelhalter test Skip
Monotony and linearity tests - Logit models imply a linear and monotonous relationship between the log odd of default and explanatory variables • Steps: • Order observations relative to each variable • Divide dataset in several subgroups • Compute for each subgroup the mean of the considered variable and the log odd of default • Run OLS: log odd against explanatory variable • Check OLS assumptions and exclude variables Back
Calibrating probabilities of default to the real portfolio - King (2001) - Adjustment to intercept only, MLE of β need not be changed: Back
Economic performance Receiver operator characteristic Cumulative accuracy profile Back
Statistical performance measures - Hosmer Lemeshow test: - Spiegelhalter test: Back
3. Methodology and input data • Methodology (3) - Measures for risk to financial stability via the direct channel:
3. Methodology and input data • Input data (1) • Explanatory variables from financial statements reported by the non-financial companies to MPF • Default information from credit register
Balance-sheet ratios • Leverage • Liquidity • Investment behavior • Size • Growth • Income statement: • Profitability • Expense Structure • Size • Growth • Mixed sources: • Cashflows • Debt coverage • ratios 3. Methodology and input data • Input data (2) • Assumption: accounting data provides an accurate picture of firms’ financial position • 40+ explanatory variables covering different financial features • Accounting issues that may impair a financial ratio’s explanatory power: • Different cost flow methods (LIFO/FIFO) • Capitalizing vs. expensing costs decisions
4. Results (1) • Model 1: 1 year probability of default at economy level
4. Results (2) • Model 1: Validation • ROC: 74.2% (in sample), 75% (out of sample), 75.3% (out of time) • Neutral cost policy function: 2.3% (cutoff), 71.7% (Hit rate), 32.7% (False alarm rate)
4. Results (3) • Model 1: 1 year probability of default dynamics
4. Results (4) • Model 1: 1 year probability of default at sector level (2006)
4. Results (5) • Model 1
4. Results (6) • Model 2: 3 years probability of default at economy level
4. Results (7) • Model 2: Validation • ROC: 74.1% (in sample), 73.12% (out of sample) • Neutral cost policy function: 5.5% (cutoff), 73.8% (Hit rate), 37.7% (False alarm rate
4. Results (8) • Model 2: 3 years (2006-2008) vs 1 year (2006) probability of default
4. Results (9) • Model 3: 1 year probability of default for large firms
4. Results (10) • Model 3: Validation • ROC: 80.57% (in sample) • HL-test: 15.88 (critical value 21) • Neutral cost policy function: 2.3% (optimal cutoff), 89.5% (hit rate), 42% (false alarm rate)
4. Results (11) • Model 3: 1 year probability of default dynamics for large firms
4. Results (12) • Model 4: 1 year probability of default for foreign trade firms
4. Results (13) • Model 4: Validation • ROC: 78.8% (in sample), 79.1% (out of sample) • Neutral cost policy function:2.3% (optimal cutoff), 68.2% (hit rate), 23.4% (false alarm rate)
4. Results (14) • Model 4: 1 year probability of default for foreign trade firms
5. Stress-testing (1) • Aspects to consider when building stress-testing scenarios: • Consistency – taking into considerations all the implications of a shock on the financial position of a firm • Methods of incorporating shocks into explanatory variables: identity relationships or estimations • Assumptions – for situations when information is not available Impact of interest rate adjustments on 1 year and 3 years probabilities of default
6. Conclusions • Determinants of default: • at economy level trade arrears, interest burden and receivables cash conversion cycle are the most frequent determinants of default • Productivity - specific determinant of default for large firms • Share of labor costs to total operating costs – specific determinant of default for foreign trade firms • Risks to financial stability: • Bank loans are concentrated into above average risk firms… • …but debt at risk is well provisioned by banks • Manufacturing and trade sectors have the lowest probability of default • Large firms are more likely to default when compared to all non-financial companies, but their effective defaulted debt is lower benign risks to financial stability • Foreign trade firms are less riskier, with importers having the lowest probability of default while exporters present the highest risk of default
6. Conclusions • Stress-testing: • We have come up with a solution to measure the impact of interest rate changes on the probability of default • Modest impact on probabilities of default even for large interest rate adjustments • Further research on this area would include: • Refining the dataset used • Improving model calibration • Accounting for correlations across firms Return
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