Underwriting Based on Cash Flow Helps Younger Entrepreneurs Access Credit

09/29/2025
Summary of working paper 33367
This figure is a scatter plot with trend lines titled "Business Owners' Ages and Loan Approval Rates." The y-axis shows loan approval rates as percentages, with a scale ranging from 18% to 28%. The x-axis shows age ranging from 26 to 70 years. The legend indicates two groups: "Owners aged 40 or younger" (shown in gray circles) and "Owners over 40" (shown in blue diamonds), with a vertical dashed line at age 40 marking the division between these groups. The figure shows two distinct trend lines with different slopes for business owners above and below age 40. For owners aged 40 or younger, each additional year of age raises approval probability by 0.29 percentage points, while for owners over 40, each additional year of age raises approval probability by 0.13 percentage points. The approval rates range from approximately 19% for the youngest owners to about 26% for the oldest owners, with a clear breakpoint at age 40 where the slope becomes less steep. The source line reads: "Source: Researchers' calculations using data from 3 anonymous fintech companies."

Younger entrepreneurs are disadvantaged in small business loan markets because lenders rely heavily on personal credit scores, which favor long histories of repaying debt. In Modernizing Access to Credit for Younger Entrepreneurs: From FICO to Cash Flow (NBER Working Paper 33367), researchers Christopher M. HairSabrina T. HowellMark J. Johnson, and Siena Matsumoto document this fact and show that younger entrepreneurs benefit from underwriting that augments personal credit scores (like FICO) with cash flow data. They analyze comprehensive data from three fintech companies serving small businesses, comprising about 1.1 million loan applications and 74,000 loans originated between 2013 and 2024.

Traditional FICO-based credit scoring can limit credit access for young entrepreneurs.

The authors show that FICO scores rise almost linearly with age—from below 670 for entrepreneurs under 30 to 720 for those over 70—while cash flow metrics show much smaller differences across age groups. Despite similar default rates after loan origination, approval rates increase significantly with entrepreneur age.

Traditional loan models rely heavily on FICO scores, while “cash-flow-enhanced” models incorporate variables from business checking accounts, such as revenue inflows, balance volatility, and financial distress indicators like overdrafts. Adding cash flow variables significantly improves default prediction, with the gain in predictive power being substantially larger for younger owners consistent with FICO being noisier and is mechanically lower for young.

The researchers show how variation in lenders' reliance on cash flow data affects loan approval probabilities. They use a causal within-application design to study what happens when the same application is sent to multiple lenders. They find that assignment to a cash-flow-intensive lender increases approval chances for entrepreneurs under 40 by 2.4 percentage points (12 percent of the mean approval rate). This effect is concentrated among low-FICO applicants and validated through business survival data, confirming that the increased approvals do not reflect excessive risk-taking by cash-flow-intensive lenders.

To identify which borrower groups benefit from switching models, the researchers develop a novel analytical framework called "Tail Analysis for Comparative Outcomes" (TACO). This method can be used by researchers and practitioners to compare any two models and is especially useful for comparing the impacts of different machine learning models without having to separately train the model on different groups. 

Comparing outcomes between a FICO-driven and a cash-flow-enhanced underwriting model, they find that entrepreneurs under 35 have a TACO ratio of 1.37, meaning 37 percent more young people benefit from switching to cash flow models than are harmed by it. For low-FICO entrepreneurs under 40, the TACO ratio reaches 2.08, indicating they are more than twice as likely to benefit from cash flow underwriting as to be harmed by it. Even among high-FICO applicants, cash flow models favor younger borrowers.


This project was partially conducted on data gathered for a project using federal funds under award MB22OBD8020266-T1-01 to FinRegLab from the Minority Business Development Agency, US Department of Commerce.