Credit Risk Analysis

Overview

Machine learning can be utilized to predict credit risk. By utilizing it, it will not only provide a quicker and more reliable loan experience but will also lead to a more accurate identification of good candidates for loans, which will lead to lower default rates. Credit risk is an inherently unbalanced classification problem, as good loans easily outnumber risky loans. Therefore, different techniques need to be employed to train and evaluate models with unbalanced classes. Numerous supervised machine learning models or algorithms have been built and evaluated to predict credit risk.

Supervised Machine Learning Models Utilized:

  • Naïve Random Oversampling
  • SMOTE Oversampling
  • Cluster Centroids Undersampling
  • SMOTEENN Combination (Over and Under) Sampling
  • Balanced Random Forest Classifier
  • Easy Ensemble ADABoost Classifier

Resources Utilized to Complete Analysis

  • Data Sources: LoanStats_2019Q1.CSV

  • Languages: Python

  • Python Dependencies: numpy, pandas, pathlib, collections, scikit-learn, imbalanced-learn

  • Tools: MS Excel, Jupyter Notebook

Results

Naïve Random Oversampling

Classification_Report_Naive_Random_Oversampling

  • Balanced Accuracy Score: 65.03%
  • Precision High Risk: 1%
  • Precision Low Risk: 100%
  • Recall High Risk: 69%
  • Recall Low Risk: 61%

Confusion Matrix

Predicted True Predicted False
Actually True 70 31
Actually False 6711 10393

SMOTE Oversampling

Classification_Report_SMOTE_Oversampling

  • Balanced Accuracy Score: 66.21%
  • Precision High Risk: 1%
  • Precision Low Risk: 100%
  • Recall High Risk: 63%
  • Recall Low Risk: 69%

Confusion Matrix

Predicted True Predicted False
Actually True 64 37
Actually False 5291 11813

Cluster Centroids Undersampling

Classification_Report_Cluster_Centroids_Undersampling

  • Balanced Accuracy Score: 54.42%
  • Precision High Risk: 1%
  • Precision Low Risk: 100%
  • Recall High Risk: 69%
  • Recall Low Risk: 40%

Confusion Matrix

Predicted True Predicted False
Actually True 70 31
Actually False 10340 6764

SMOTEENN Combination (Over and Under) Sampling

Classification_Report_SMOTEENN_Combination_Sampling

  • Balanced Accuracy Score: 64.61%
  • Precision High Risk: 1%
  • Precision Low Risk: 100%
  • Recall High Risk: 71%
  • Recall Low Risk: 58%

Confusion Matrix

Predicted True Predicted False
Actually True 72 29
Actually False 7195 9909

Balanced Random Forest Classifier

Classification_Report_Balanced_Random_Forest_Classifier

  • Balanced Accuracy Score: 78.85%
  • Precision High Risk: 3%
  • Precision Low Risk: 100%
  • Recall High Risk: 70%
  • Recall Low Risk: 87%

Confusion Matrix

Predicted True Predicted False
Actually True 71 30
Actually False 2153 14951

Easy Ensemble ADABoost Classifier

Classification_Report_Easy_Ensemble_ADABoost_Classifier

  • Balanced Accuracy Score: 93.16%
  • Precision High Risk: 9%
  • Precision Low Risk: 100%
  • Recall High Risk: 92%
  • Recall Low Risk: 94%

Confusion Matrix

Predicted True Predicted False
Actually True 93 8
Actually False 983 16121

Summary

Numerous machine learning models were utilized to determine which model is the most effective at predicting credit risk. Accuracy, precision and sensitivity can be assessed by reviewing the results of each model. The confusion matrix, collates the results of accuracy,precision and sensitivity and can be calculated as follows: 

Confusion Matrix

Predicted True Predicted False
Actually True TP FN
Actually False FP TN
  • Accuracy = (True Positives (TP) + True Negatives (TN)) / Total
  • Precision = True Positives (TP) / (True Positives (TP) + False Positives (FP))
  • Sensitivity = True Positives (TP) / (True Positives (TP) + False Negatives (FN)) 

The analysis highlighted above, indicates that the precision scores for all the models are overfit. A good balance of recall and precision is necessary to have an effective model and most of the models lack this. However, the Easy Ensemble ADABoost Classifier model is recommended for use, due to its high balanced accuracy score, along with its balance of precision and recall scores.