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1 | (39) |
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1.1 Alternative Perspectives |
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3 | (8) |
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1.1.1 Pricing or Risk-Management? |
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3 | (3) |
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1.1.2 Minding our P's and Q's |
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6 | (1) |
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1.1.3 Instruments or Portfolios? |
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7 | (2) |
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9 | (1) |
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1.1.5 Type of Credit-Risk Model |
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10 | (1) |
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1.1.6 Clarifying Our Perspective |
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11 | (1) |
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11 | (7) |
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1.2.1 Modelling Implications |
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13 | (2) |
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15 | (3) |
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18 | (6) |
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1.3.1 Modelling Frameworks |
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19 | (2) |
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21 | (2) |
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1.3.3 Estimation Techniques |
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23 | (1) |
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24 | (1) |
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24 | (2) |
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26 | (1) |
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1.6 A Quick Pre-Screening |
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27 | (10) |
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1.6.1 A Closer Look at Our Portfolio |
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27 | (2) |
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1.6.2 The Default-Loss Distribution |
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29 | (1) |
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1.6.3 Tail Probabilities and Risk Measures |
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30 | (3) |
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33 | (4) |
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37 | (1) |
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37 | (1) |
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38 | (2) |
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Part I Modelling Frameworks |
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40 | (1) |
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41 | (44) |
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2.1 Motivating a Default Model |
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42 | (8) |
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45 | (1) |
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2.1.2 Multiple Instruments |
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46 | (4) |
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50 | (1) |
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50 | (17) |
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53 | (2) |
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2.2.2 A Numerical Solution |
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55 | (7) |
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2.2.3 An Analytical Approach |
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62 | (5) |
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2.3 Convergence Properties |
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67 | (6) |
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73 | (9) |
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82 | (1) |
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82 | (3) |
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3 Mixture or Actuarial Models |
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85 | (64) |
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3.1 Binomial-Mixture Models |
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86 | (27) |
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3.1.1 The Beta-Binomial Mixture Model |
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92 | (9) |
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3.1.2 The Logit-and Probit-Normal Mixture Models |
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101 | (12) |
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3.2 Poisson-Mixture Models |
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113 | (18) |
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3.2.1 The Poisson-Gamma Approach |
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115 | (10) |
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3.2.2 Other Poisson-Mixture Approaches |
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125 | (4) |
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3.2.3 Poisson-Mixture Comparison |
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129 | (2) |
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131 | (16) |
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3.3.1 A One-Factor Implementation |
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131 | (10) |
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3.3.2 A Multi-Factor CreditRisk+ Example |
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141 | (6) |
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147 | (1) |
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148 | (1) |
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149 | (80) |
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150 | (15) |
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4.1.1 The Latent Variable |
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150 | (2) |
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4.1.2 Introducing Dependence |
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152 | (2) |
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4.1.3 The Default Trigger |
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154 | (1) |
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155 | (3) |
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4.1.5 Default Correlation |
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158 | (3) |
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161 | (1) |
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4.1.7 Gaussian Model Results |
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162 | (3) |
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4.2 The Limit-Loss Distribution |
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165 | (10) |
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4.2.1 The Limit-Loss Density |
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170 | (2) |
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4.2.2 Analytic Gaussian Results |
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172 | (3) |
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175 | (7) |
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4.3.1 The Tail-Dependence Coefficient |
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176 | (3) |
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4.3.2 Gaussian Copula Tail-Dependence |
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179 | (1) |
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4.3.3 t-Copula Tail-Dependence |
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180 | (2) |
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4.4 The t-Distributed Approach |
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182 | (11) |
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4.4.1 A Revised Latent-Variable Definition |
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182 | (4) |
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4.4.2 Back to Default Correlation |
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186 | (2) |
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4.4.3 The Calibration Question |
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188 | (2) |
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4.4.4 Implementing the t-Threshold Model |
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190 | (3) |
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4.4.5 Pausing for a Breather |
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193 | (1) |
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4.5 Normal-Variance Mixture Models |
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193 | (18) |
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4.5.1 Computing Default Correlation |
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197 | (1) |
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198 | (2) |
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200 | (1) |
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4.5.4 The Variance-Gamma Model |
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201 | (1) |
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4.5.5 The Generalized Hyperbolic Case |
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202 | (2) |
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4.5.6 A Fly in the Ointment |
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204 | (2) |
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4.5.7 Concrete Normal-Variance Results |
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206 | (5) |
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4.6 The Canonical Multi-Factor Setting |
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211 | (7) |
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4.6.1 The Gaussian Approach |
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211 | (3) |
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4.6.2 The Normal-Variance-Mixture Set-Up |
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214 | (4) |
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4.7 A Practical Multi-Factor Example |
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218 | (7) |
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4.7.1 Understanding the Nested State-Variable Definition |
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219 | (2) |
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4.7.2 Selecting Model Parameters |
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221 | (3) |
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4.7.3 Multivariate Risk Measures |
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224 | (1) |
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225 | (1) |
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226 | (3) |
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5 The Genesis of Credit-Risk Modelling |
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229 | (57) |
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230 | (10) |
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5.1.1 Introducing Asset Dynamics |
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233 | (3) |
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5.1.2 Distance to Default |
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236 | (2) |
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5.1.3 Incorporating Equity Information |
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238 | (2) |
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5.2 Exploring Geometric Brownian Motion |
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240 | (5) |
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245 | (2) |
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246 | (1) |
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5.4 The Indirect Approach |
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247 | (8) |
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5.4.1 A Surprising Simplification |
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249 | (2) |
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5.4.2 Inferring Key Inputs |
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251 | (1) |
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5.4.3 Simulating the Indirect Approach |
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252 | (3) |
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255 | (25) |
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5.5.1 Expected Value of An, T |
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257 | (2) |
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5.5.2 Variance and Volatility of An, T |
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259 | (2) |
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5.5.3 Covariance and Correlation of An, T and Am, T |
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261 | (2) |
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5.5.4 Default Correlation Between Firms n and m |
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263 | (2) |
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5.5.5 Collecting the Results |
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265 | (1) |
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5.5.6 The Task of Calibration |
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265 | (5) |
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5.5.7 A Direct-Approach Inventory |
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270 | (1) |
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5.5.8 A Small Practical Example |
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270 | (10) |
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280 | (2) |
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282 | (4) |
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286 | (1) |
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6 A Regulatory Perspective |
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287 | (64) |
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288 | (15) |
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290 | (2) |
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6.1.2 The Basic Structure |
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292 | (3) |
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6.1.3 A Number of Important Details |
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295 | (5) |
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300 | (3) |
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303 | (6) |
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306 | (3) |
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6.3 The Granularity Adjustment |
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309 | (39) |
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311 | (1) |
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6.3.2 A Complicated Add-On |
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312 | (5) |
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6.3.3 The Granularity Adjustment |
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317 | (1) |
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6.3.4 The One-Factor Gaussian Case |
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318 | (7) |
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6.3.5 Getting a Bit More Concrete |
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325 | (3) |
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6.3.6 The CreditRisk+ Case |
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328 | (12) |
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340 | (6) |
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346 | (2) |
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348 | (3) |
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351 | (78) |
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352 | (3) |
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7.2 A Surprising Relationship |
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355 | (13) |
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357 | (4) |
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361 | (3) |
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7.2.3 Some Illustrative Results |
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364 | (2) |
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7.2.4 A Shrewd Suggestion |
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366 | (2) |
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7.3 The Normal Approximation |
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368 | (4) |
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7.4 Introducing the Saddlepoint Approximation |
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372 | (12) |
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373 | (3) |
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7.4.2 The Density Approximation |
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376 | (2) |
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7.4.3 The Tail Probability Approximation |
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378 | (3) |
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381 | (1) |
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7.4.5 A Bit of Organization |
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382 | (2) |
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7.5 Concrete Saddlepoint Details |
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384 | (10) |
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7.5.1 The Saddlepoint Density |
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388 | (3) |
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7.5.2 Tail Probabilities and Shortfall Integralls |
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391 | (1) |
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392 | (1) |
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7.5.4 Illustrative Results |
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393 | (1) |
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7.6 Obligor-Level Risk Contributions |
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394 | (12) |
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7.6.1 The VaR Contributions |
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395 | (5) |
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7.6.2 Shortfall Contributions |
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400 | (6) |
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7.7 The Conditionally Independent Saddlepoint Approximation |
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406 | (15) |
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412 | (3) |
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7.7.2 A Multi-Model Example |
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415 | (5) |
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7.7.3 Computational Burden |
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420 | (1) |
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7.8 An Interesting Connection |
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421 | (5) |
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426 | (1) |
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426 | (3) |
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429 | (62) |
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430 | (1) |
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8.2 A Silly, But Informative Problem |
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431 | (8) |
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8.3 The Monte Carlo Method |
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439 | (6) |
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8.3.1 Monte Carlo in Finance |
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440 | (4) |
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8.3.2 Dealing with Slowness |
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444 | (1) |
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445 | (5) |
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8.4.1 A Rough, But Workable Solution |
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445 | (2) |
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8.4.2 An Example of Convergence Analysis |
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447 | (3) |
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450 | (1) |
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8.5 Variance-Reduction Techniques |
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450 | (35) |
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8.5.1 Introducing Importance Sampling |
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451 | (2) |
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8.5.2 Setting Up the Problem |
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453 | (4) |
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8.5.3 The Esscher Transform |
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457 | (3) |
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460 | (2) |
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8.5.5 Implementing the Twist |
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462 | (5) |
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467 | (7) |
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474 | (2) |
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8.5.8 Tying Up Loose Ends |
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476 | (3) |
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479 | (6) |
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485 | (1) |
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486 | (5) |
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Part III Parameter Estimation |
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491 | (84) |
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9.1 Some Preliminary Motivation |
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492 | (6) |
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9.1.1 A More Nuanced Perspective |
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493 | (5) |
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498 | (46) |
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9.2.1 A Useful Mathematical Object |
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499 | (7) |
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506 | (2) |
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508 | (3) |
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9.2.4 Hazard-Rate Approach |
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511 | (1) |
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9.2.5 Getting More Practical |
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512 | (1) |
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9.2.6 Generating Markov-Chain Outcomes |
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513 | (5) |
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9.2.7 Point Estimates and Transition Statistics |
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518 | (5) |
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9.2.8 Describing Uncertainty |
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523 | (15) |
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538 | (3) |
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9.2.10 Risk-Metric Implications |
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541 | (3) |
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9.3 Risk-Neutral Default Probabilities |
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544 | (23) |
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9.3.1 Basic Cash-Flow Analysis |
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544 | (3) |
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9.3.2 Introducing Default Risk |
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547 | (6) |
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9.3.3 Incorporating Default Risk |
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553 | (4) |
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9.3.4 Inferring Hazard Rates |
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557 | (4) |
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561 | (6) |
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9.4 Back to Our P's and Q's |
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567 | (4) |
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571 | (1) |
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571 | (4) |
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10 Default and Asset Correlation |
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575 | (62) |
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10.1 Revisiting Default Correlation |
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576 | (4) |
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10.2 Simulating a Dataset |
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580 | (9) |
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10.2.1 A Familiar Setting |
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581 | (6) |
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10.2.2 The Actual Results |
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587 | (2) |
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10.3 The Method of Moments |
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589 | (6) |
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10.3.1 The Threshold Case |
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593 | (2) |
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595 | (20) |
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596 | (2) |
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10.4.2 A One-Parameter Example |
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598 | (4) |
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602 | (4) |
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10.4.4 A More Complicated Situation |
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606 | (9) |
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10.5 Transition Likelihood Approach |
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615 | (18) |
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10.5.1 The Elliptical Copula |
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616 | (6) |
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10.5.2 The Log-Likelihood Kernel |
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622 | (4) |
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10.5.3 Inferring the State Variables |
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626 | (2) |
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628 | (5) |
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633 | (1) |
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634 | (3) |
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637 | (12) |
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A.1 The Chi-Squared Distribution |
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638 | (1) |
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A.2 Toward the t-Distribution |
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639 | (4) |
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A.3 Simulating Correlated t Variates |
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643 | (4) |
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647 | (2) |
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B The Black-Scholes Formula |
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649 | (10) |
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B.1 Changing Probability Measures |
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649 | (4) |
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B.2 Solving the Stochastic Differential Equation |
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653 | (2) |
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B.3 Evaluating the Integral |
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655 | (3) |
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658 | (1) |
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659 | (8) |
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659 | (2) |
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661 | (2) |
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663 | (4) |
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D The Python Code Library |
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667 | (8) |
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D.1 Explaining Some Choices |
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668 | (1) |
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D.2 The Library Structure |
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669 | (2) |
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671 | (1) |
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672 | (1) |
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673 | (2) |
Index |
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675 | (6) |
Author Index |
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681 | |