In cross-sectional data sets from ten credit markets, we find that middle-aged adults borrow at lower interest rates and pay fewer fees relative to younger and older adults. Fee and interest payments are minimized around age 53. The measured effects are not explained by observed risk...

We use extreme value theory (EVT) to develop insights about price theory. Our analysis reveals "detail-independent" equilibrium properties that characterize a large family of models. We derive a formula relating equilibrium prices to the level of competition. When the number of firms is large,...

In many markets consumer biases do not affect prices, since competition forces firms to price their products close to marginal cost; competition protects the consumer. We show that noisy consumer product evaluations undermine the force of competition, enabling firms to charge high mark-ups in...

Some consumers fail to observe shrouded product attributes when they buy a new product. For example, an account holder may not know their bank's fee schedule. Firms will choose high shrouded fees and compete to attract consumers with loss-leader base goods: e.g., banks will offer free gifts for...

Bayesian consumers infer that hidden add-on prices (e.g. the cost of ink for a printer) are likely to be high prices. If consumers are Bayesian, firms will not shroud information in equilibrium. However, shrouding may occur in an economy with some myopic (or unaware) consumers. Such shrouding...

Agents with more experience make better choices. We measure learning dynamics using a panel with four million monthly credit card statements. We study add-on fees, specifically cash advance, late payment, and overlimit fees. New credit card accounts generate fee payments of $15 per month....