The article examines how different factors influence the likelihood of default in residential mortgage lending in Russia. By analyzing data from a specific agency over a period of five years, the researchers found that borrower and loan characteristics, as well as the overall economic situation, play a significant role in predicting loan performance. Surprisingly, borrowers with undisclosed income were found to have the lowest chance of default, likely due to discrepancies between their reported and actual income. These findings were consistent across different statistical models and were adjusted for potential biases in the data.