This thesis consists of two essays on household finance and one essay on innovation. Chapter 1 examines descriptively how UK credit card lenders set credit limits and interest rates for customers. First, I summarize the literature on credit card regulation and lenders’ choices of credit limits and interest rates. Second, I detail the relevant credit card regulation, focusing on how UK credit card lenders are required to advertize a “representative” interest rate for every credit card product they offer. Third, I describe my credit card dataset together with basic summary statistics. Finally, I offer a set of descriptive findings. My main results describe the limited variation in interest rates within credit card products relative to substan...