Everything is relative. $1,000 balance is a lot of money for someone making $35,000, not so much for someone making $350,000. Many independent variables that go

Everything is relative. $1,000 balance is a lot of money for someone making $35,000, not so much for someone making $350,000. Many independent variables that go into risk scores tend to be ratios or averages, hence zero (or near zero) denominator is possible. It is normally addressed with floors and ceilings or something like Laplace rule of succession, so that no data at all results in a reasonable number. Very rarely that reasonable number is zero. I'm not saying taking the average is necessarily good in the examples given, just that if you are computing the average, then that computation should not silently return zero if there's no data to average. That's the way AVG() in SQL or mean() in R work, they return NULL or NA rather than 0. If you know that NA should be 0 you can explicitly COALESCE, but that should be your decision rather than the default behavior.