Automated underwriting and the profitability of mortgage securitization

This paper develops a game-theoretic model of mortgage securitization, which is then used to examine a potential effect of automated underwriting. The paper's primary supposition is that automated underwriting lowers the costs to competitive mortgage originators and a monopolist securitizer of identifying mortgage applicants who are good credit risks. Faced with lower underwriting costs, originators will screen a larger number of mortgage applicants in the hopes of holding more good risks in their portfolios and passing through more bad risks to the securitizer. This mounting adverse-selection problem causes the securitizer's expected revenues to decline; this effect can outweigh the cost-saving benefit of automated underwriting, causing the securitizer's return on equity to fall.