Validation of statistical Model used for HPI scenario expansion for a US based G-SIB

Client : A G-SIB based in North America

 

Objective

 

  • The scope of the engagement was to validate the statistical model used for HPI scenarios expansion
  • The model used simple linear regression model to expand national level (US) HPI to (51) state level HPI in 5 different CCAR scenarios – the model used different equation for stress and normal period

 

CRISIL's solution

 

  • Data Preparation: Quarterly HPI forecast was converted to monthly to predict monthly state-wise HPI
  • Validation Approach: (i) review of model development document, implementation file, and data integrity; (ii) review of conceptual soundness; and (iii) review of model governance
  • Goodness of Fit and Outcome Analysis: Serial correlation, heteroscedasticity, causality, structural break, etc., were examined for all the models. Out-of-sample statistics, out-of-time validations, backtesting, sensitivity analysis, and stress testing methods were used to ensure the model is appropriate. This included a few graphs and error tests/tables

 

Client impact

 

  • Validated the entire model within stringent timelines, and created extensive and thorough documentation for regulatory submission

Questions



Looking for high-end research and risk services? Reach out to us at:

 

United States
1-855-595-2100/
+1 646 292 3520

 

United Kingdom
+44 (0) 870 333 6336

India
+91 22 33 42 3000 /
+91 22 61 72 3000