#averages

¶ My model has ‘the average borrower’. Nobody is the average borrower. What am I talking about?

I build credit-scoring models for a mobile-money company in Nairobi. Every week I write sentences like "the average borrower in this segment repays within 23 days" or "the typical applicant has 2.4 active SIM cards". Everyone understands them. No borrower repays in…