Loan Approval Process Analysis

Author

Brandon Hao

Task 1

\[\Large \textbf{Section 1}\]

         (Intercept)             constant    previous_mortgage 
         1.096335057                   NA          0.052572666 
   unemployment_rate relative_loan_amount 
        -0.007939107         -0.002693301 

\[\Large \textbf{Section 2}\]

For Beta_2 (previous_mortgage), the 95% confidence interval is [ 0.0752 , 0.3454 ]
For Beta_3 (relative_loan_amount), the 95% confidence interval is [ -0.0142 , -0.0073 ]

\[\Large \textbf{Section 3}\]

\[\Large \textbf{Analysis}\]

The R script provided for the analysis of loan approval processes employs a linear regression model to determine the influence of various factors on loan approval chances. The dataset, binary_loan.csv, includes variables such as previous mortgage, unemployment rate, and relative loan amount. These predictors are crucial in evaluating their effects on the binary outcome variable, approval.

The regression model introduced in Task 1 is enhanced by adding a constant to serve as the intercept, along with the primary predictors. The coefficient outputs indicate each variable's impact on loan approval probability. The positive coefficient (0.0526) for previous mortgage suggests that possessing a previous mortgage slightly raises the chances of obtaining a new loan. In contrast, the coefficients for unemployment rate (-0.0079) and relative loan amount (-0.0027) are negative, indicating these factors reduce the likelihood of loan approval.

A notable point in the model output is the absence of a coefficient for the constant term (listed as NA), which might point to issues of collinearity or redundancy. This suggests the need to reevaluate the inclusion of a manually added constant, as it might be leading to inaccuracies in the model's interpretation.

In Tasks 3 and 4, confidence intervals for the coefficients of previous mortgage and relative loan amount are calculated to determine the precision of these estimates. These intervals provide a statistical range that is likely to contain the true coefficient values with a 95% confidence level. For previous mortgage, the confidence interval spans from 0.0752 to 0.3454, confirming its positive influence on loan approval. The confidence interval for relative loan amount is entirely negative, ranging from -0.0142 to -0.0073, solidifying its inverse relationship with loan approval probabilities.

The script applies a factor of four to the standard errors during the calculation of these confidence intervals in Task 3, which may serve as a robustness check or to address potential model misspecification issues like heteroscedasticity.

The explanation section in Task 4 sheds light on the implications of these coefficient signs. A positive Beta2 for previous mortgage suggests that applicants with a history of mortgages are seen as less risky, which could be interpreted by lenders as a sign of financial reliability or stability. On the other hand, the negative Beta3 associated with relative loan amount indicates that higher loan requests relative to the applicant's financial status are viewed as riskier by lenders, leading to lower approval rates.

This analysis provides vital insights for lenders and financial analysts, highlighting the significant role of an applicant’s financial history and current economic conditions in the decision-making process for loan approvals. The positive association of previous mortgage with loan approval rates could encourage lenders to weigh historical financial behavior more heavily. Simultaneously, the adverse effects of higher relative loan amounts and poor economic conditions could guide the development of more nuanced lending criteria.

For further refinement, exploring additional predictors and incorporating logistic regression could yield a more detailed understanding of the factors influencing loan approval. This approach would suit the binary nature of the outcome variable more aptly, offering a clearer depiction of how various elements contribute to the likelihood of loan approval in real-world lending scenarios.