The alliance used what is known as standard paired testing, where two testers -- one white and one nonwhite -- entered a dealership and inquired about buying or obtaining financing for the same car, down to the same vehicle identification number. The testers arrived at the dealership within 24 hours of each other on weekdays early in the month to avoid end-of-month pricing deals.
In each case, the nonwhite tester had a better credit score. In seven of the eight pairs, the nonwhite tester also had a higher income. In the other test pair, the nonwhite tester's income was less than that of the white tester, but the nonwhite tester had a better debt-to-income ratio.
The testers within each pair sought the same down payment, asked for the same monthly payment and were instructed to avoid asking for a specific loan term. Each tester also was trained to ask one time if the quoted monthly payment option was at the best interest rate the dealer could provide but otherwise was instructed not to negotiate or haggle the price, rate, term or other features. Testers also were instructed to reject any warranties and add-ons.
The testers were paired to be similar based on age, gender and other factors that would make them eligible for discounts, such as military affiliation or recent college graduation.