base rate

Meanings

1. A benchmark interest rate, from which other interest rates are calculated; a policy rate.
2. Especially, the interest rate at which the Bank of England lends money to commercial banks.
3. The background rate of occurrence of any phenomenon, which informs any logical analysis of its rate of occurrence under any subset of circumstances; especially, the proportion of individuals in a population who have a certain characteristic (e.g., trait, experience, circumstance), irrespective of any treatment effects in a treatment group of a scientific study.