An optimization problem has to be solved by adjusting the threshold and seeking the optimum in order to balance the trade-off between the decrease in revenue and a decrease in cost.

An optimization problem has to be solved by adjusting the threshold and seeking the optimum in order to balance the trade-off between the decrease in revenue and a decrease in cost.

If “Settled” means good and “Past Due” is described as negative, then utilizing the design associated with the confusion matrix plotted in Figure 6, the four areas are split as real Positive (TN), False Positive (FP), False bad (FN) and real Negative (TN). Aligned with all the confusion matrices plotted in Figure 5, TP could be the loans that are good, and FP may be the defaults missed. Our company is interested in those two areas. To normalize the values, two widely used mathematical terms are defined: real good Rate (TPR) and False Positive Rate (FPR). Their equations are shown below:

In this application, TPR may be the hit rate of great loans, plus it represents the capacity of creating https://www.badcreditloanshelp.net/payday-loans-ar/lepanto/ funds from loan interest; FPR is the lacking rate of standard, and it also represents the likelihood of losing profits.

Receiver Operational Characteristic (ROC) bend is one of commonly used plot to visualize the performance of the category model at all thresholds. In Figure 7 left, the ROC Curve associated with Random Forest model is plotted. This plot basically shows the connection between TPR and FPR, where one always goes into the same way as one other, from 0 to at least one. a classification that is good would also have the ROC curve over the red standard, sitting because of the “random classifier”. The region Under Curve (AUC) can also be a metric for assessing the category model besides precision. The AUC regarding the Random Forest model is 0.82 away from 1, that is decent.

Although the ROC Curve plainly shows the partnership between TPR and FPR, the limit can be an implicit variable. The optimization task cannot purely be done because of the ROC Curve. Consequently, another measurement is introduced to add the limit adjustable, as plotted in Figure 7 right. Because the orange TPR represents the capacity of creating cash and FPR represents the opportunity of losing, the instinct is to look for the threshold that expands the gap between curves whenever you can. In this instance, the sweet spot is just about 0.7.

You will find restrictions for this approach: the FPR and TPR are ratios. Also we still cannot infer the exact values of the profit that different thresholds lead to though they are good at visualizing the impact of the classification threshold on making the prediction. Having said that, the FPR, TPR vs Threshold approach makes the assumption that the loans are equal (loan quantity, interest due, etc.), however they are really perhaps not. Those who default on loans could have a greater loan quantity and interest that have to be repaid, also it adds uncertainties towards the results that are modeling.

Luckily, step-by-step loan amount and interest due are offered by the dataset it self.

The thing staying is to get a method to link these with the threshold and model predictions. It’s not tough to determine a manifestation for revenue. These two terms can be calculated using 5 known variables as shown below in Table 2 by assuming the revenue is solely from the interest collected from the settled loans and the cost is solely from the total loan amount that customers default

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