Some Ethical Issues in Computation and Disclosure of Interest Rate and Cost of Credit

Although the mathematics of interest is very precise, the practice of charging computing and disclosing interest or cost of credit is full of variations and therefore often questionable on ethical grounds. The purpose of this paper is to examine some of the prevalent practices which are incorrect, illogical, unfair or deceptive. Both utilitarian and formalist schools of ethical theory would find these practices to be inappropriate. The paper will specifically look at unfair practices in the areas of estimation of intrayear rates, use of 360 days in a year, the "rule of 78th", interest rate ('APR') advertising, and computation of unpaid balance by credit card issuers to figure interest costs.