The Business of Lending

Every time a bank approves a loan, it is making a bet: that you will pay the money back, plus interest, on schedule. If the bank is right, it earns a return. If it is wrong, it loses the money it lent you. The entire lending industry is built on making this bet correctly, millions of times over.

Banks borrow money cheaply (from depositors and wholesale markets) and lend it at higher rates. The difference, called the spread, is their primary revenue. But some borrowers do not pay back. When that happens, the bank loses not just the interest but the principal. Too many defaults and the bank is insolvent.

Interest Rates as Risk Pricing

Lenders charge different rates to different people, and the reason is math. A borrower who is very likely to repay gets a low rate (say 5%). A riskier borrower gets a higher rate (say 15%). A borrower the lender expects will default gets denied entirely.

Why higher rates for riskier borrowers? Consider 100 borrowers each taking a $10,000 loan. If 2 out of 100 default, the lender loses $20,000. The interest from the other 98 must cover that loss plus costs plus profit. If 10 out of 100 default, the lender loses $100,000, and rates on the other 90 must be much higher to make the math work. The rate IS the risk.

The lender's goal is not to avoid risk entirely. A lender that only approves the safest 10% of applicants leaves enormous revenue on the table. The goal is to price risk accurately: set rates that compensate for actual default probability and lend to as many people as possible at rates that work for both sides.

Credit Scores: The Sorting Tool

How do you evaluate millions of loan applicants quickly? For the past 35 years, the answer has been the credit score. The most common is the FICO score: a number between 300 and 850 summarizing your credit history. High score means you have a track record of paying back debt on time. Low score means you do not.

Lenders set cutoffs. Above 720 is usually "prime" (best rates). Between 620 and 720 is "near-prime." Below 620 is "subprime" (high rates or denial). These cutoffs determine who gets access to affordable credit and who does not.

The Access Problem

Credit scores work well for people with long, documented credit histories. They fail for everyone else.

According to the Consumer Financial Protection Bureau, 26 million American adults are "credit invisible" (no credit file at all) and another 19 million are "unscorable" (too thin to generate a score). These 45 million people are not necessarily bad risks. Many are recent graduates, immigrants, cash-economy workers, or people who have simply never borrowed. They are invisible to the system.

The promise of better algorithms What if lenders could assess risk using more data and more sophisticated analysis? They could approve the recent graduate who always made student loan and rent payments on time. They could serve the immigrant who ran a successful business abroad. They could reach the gig worker whose bank account shows steady deposits. Better algorithms do not just help lenders make more money. They give people fair access to credit they can actually handle.

When Scoring Goes Wrong

In the years before the 2008 financial crisis, mortgage lenders approved millions of borrowers who could not actually afford their loans. Many had credit scores that looked adequate: they had some credit history and were current on existing accounts. But the scores did not capture their ability to pay under stress: what happens when the adjustable rate resets, when housing prices drop, when they lose a job.

When housing prices fell, millions defaulted. Many were recent immigrants and first-time buyers with "thin file" credit profiles who had been sold mortgages they did not understand and could not sustain. The scoring system failed both the borrowers (who lost their homes) and the lenders (who lost billions).

The lesson: a score that does not capture real ability to pay is dangerous for everyone. The three approaches that follow represent three different attempts to score more accurately.

Approach 1: Traditional FICO Scoring

The FICO score was introduced in 1989 by Fair Isaac Corporation. Before FICO, lending decisions were local and subjective: a loan officer would interview you, check your references, and make a judgment call. This system was slow, expensive, and rife with discrimination. FICO replaced subjective judgment with a standardized number.

The Five Factors

  1. Payment History (35%): Have you paid bills on time? Late payments, collections, and bankruptcies pull this down.
  2. Credit Utilization (30%): How much of your available credit are you using? Using $3,000 of a $10,000 limit (30%) is fine. Using $9,000 (90%) signals strain.
  3. Length of Credit History (15%): How long have your accounts been open? Longer history means more data.
  4. New Credit (10%): Have you opened many new accounts recently? Multiple applications in a short period can signal desperation.
  5. Credit Mix (10%): Do you have different types of credit (cards, auto loan, mortgage)? Diversity suggests experience.

Try It: FICO Score Simulator

Select an applicant to see how FICO evaluates their credit profile.

Strengths

Weaknesses

Approach 2: Machine Learning Lending

Upstart was founded in 2012 by former Google employees with a hypothesis: machine learning models trained on thousands of variables could predict loan defaults more accurately than FICO's formula. They were right. The results earned a no-action letter from the Consumer Financial Protection Bureau in 2017, giving regulatory clearance to use education and employment data in lending decisions.

What ML Adds to Credit Scoring

Upstart starts with the same credit data FICO uses, then layers on:

The ML model (gradient-boosted trees, not a single formula) processes over 1,600 variables versus FICO's ~30. It finds non-obvious patterns: correlations between specific education/employment combinations and default rates that no human analyst would think to code as rules.

Try It: FICO vs. Upstart Comparison

Select an applicant to see how the two systems evaluate the same person.

The Results

By the numbers According to Upstart's public data, their ML model produces 75% fewer defaults at the same approval rate, OR 27% more approvals at the same default rate. The biggest beneficiaries: young borrowers, thin-file applicants, and people with non-traditional career paths.

The Bias Question

ML models find any pattern that predicts default, including patterns correlated with race, even when race is not an input variable. ZIP code, university attended, and field of study can serve as proxies for protected characteristics. If graduates of historically Black colleges default at different rates (for any reason, including systemic inequity), the model will pick up that pattern.

The debate is ongoing: does ML lending reduce bias (by finding creditworthy people FICO misses) or amplify it (by finding new proxies for discrimination)? Evidence suggests it does both, depending on implementation. The regulatory framework is still evolving.

Approach 3: Alternative Data Lending

FICO requires credit history. Upstart requires credit history plus more. Tala requires neither. Founded in 2014, Tala operates in Kenya, the Philippines, Mexico, and India, serving people who have zero formal credit history. Its approach: use smartphone behavioral data to assess creditworthiness from scratch.

The Unbanked Problem

According to the World Bank, approximately 1.4 billion adults worldwide have no bank account. In sub-Saharan Africa, only about 55% of adults have any formal financial account. These people have legitimate credit needs (business inventory, medical emergencies, school fees) but no way to prove creditworthiness under traditional systems.

What Tala Analyzes

When a user applies for a Tala loan, the app (with permission) analyzes behavioral signals from their smartphone:

Try It: What Does Tala See?

Select a borrower to see how phone behavioral data becomes a credit assessment.

The Results

Tala has disbursed over $4 billion in loans since 2014. Average loan sizes are small ($50 to $200) because these are first-time borrowers building a track record. Default rates are competitive with traditional microlenders. For millions of users, a Tala loan is their first interaction with formal credit.

The Privacy Tradeoff

What you give up Tala's model requires access to your contacts, location, app usage, and communication patterns. This is far more invasive than a traditional credit check. The exchange is explicit: share your behavioral data, get access to credit you could not get otherwise. For someone with no alternatives, this may be worth it. But the data infrastructure could be used for purposes beyond lending, and regulatory frameworks for this type of collection barely exist in most markets.