This Framing Note is the fourth in a policy series by the Financial Access Initiative exploring various dilemmas which policymakers face across several topics of great importance to financial inclusion. This paper describes the contours of the interest rate policy dilemma, updating previous sources with new theory about consumer behavior and new evidence from the demand side about how clients respond to interest rates; and from the supply side as to what drives the setting of rates. The focus here is not on interest rate policy in general, which would include its use in monetary policy, but rather the interest rate control regime applied especially to small or micro loans.