" Where to find the borrowers with high FICO scores? Here the Wall Street bond trading desks exploited another blind spot in the rating agencies’ models. Apparently the agencies didn’t grasp the difference between a “thin-file” FICO score and a “thick-file” FICO score. A thin-file FICO score implied, as it sounds, a short credit history. The file was thin because the borrower hadn’t done much borrowing. Immigrants who had never failed to repay a debt, because they had never been given a loan, often had surprisingly high thin-file FICO scores. Thus a Jamaican baby nurse or Mexican strawberry picker with an income of $14,000 looking to borrow three-quarters of a million dollars, when filtered through the models at Moody’s and S&P, became suddenly more useful, from a credit-rigging point of view. They might actually improve the perceived quality of the pool of loans and increase the percentage that could be declared triple-A. The Mexican harvested strawberries; Wall Street harvested his FICO score. "

― Michael Lewis