Many policymakers and some theories hold that restricting access to expensive credit helps consumers by preventing overborrowing. I examine some effects of restricting access, using household panel survey data on payday loan users collected around the introduction of binding restrictions on payday loan terms in Oregon. Borrowing fell in Oregon relative to Washington, with former payday borrowers shifting partially into plausibly inferior substitutes: bank overdrafts and late bill payment. Additional evidence suggests that restricting access caused deterioration in the overall financial condition of Oregon households. Overall the results are consistent with restricted access harming, not helping, consumers on average.

Empirical consumer payment price sensitivity has implications for theory, optimal regulation of payment card networks, and business strategy. A critical margin is the price of a credit card charge. A revolver who did not pay her most recent balance in full pays interest; other credit card users do not. I find that revolvers are substantially less likely to incur credit card charges and substantially more likely to use a debit card, conditional on several proxies for transaction demand and tastes. Debit use also increases with credit limit constraints and decreases with credit card possession. Additional results suggest that debit is becoming a stronger substitute for credit over time.

We document substantial cross-individual dispersion in U.S. credit card borrowing costs, even after controlling for borrower risk and card characteristics. That remaining dispersion arises because cross-lender pricing heterogeneity generates dispersion in annual percentage rate (APR) offers to borrowers, and borrowers vary in shopping intensity. Our empirics match administrative data to self-reported card shopping intensity and use instruments suggested by fair lending law to account for the endogeneity between APRs and search. The results show that shoppers versus nonshoppers pay APRs as different as those paid by borrowers in the best versus worst credit score deciles. We discuss implications for policy and practice.

Does borrowing at 400% APR do more harm than good? The U.S. Department of Defense thinks so and successfully lobbied for a 36% APR cap on loans to servicemen. But existing evidence on how access to high-interest debt affects borrowers is inconclusive. We estimate effects of payday loan access on enlisted personnel using exogenous variation in Air Force rules assigning personnel to bases across the United States, and within-state variation in lending laws over time. Airmen job performance and retention declines with payday loan access, and severely poor readiness increases. These effects are strongest among relatively inexperienced and financially unsophisticated airmen.

We explore dynamics of limited attention in the $35 billion market for checking overdrafts, using survey content as shocks to the salience of overdraft fees. Conditional on selection into surveys, individuals who face overdraft-related questions are less likely to incur a fee in the survey month. Taking multiple overdraft surveys builds a "stock" of attention that reduces overdrafts for up to two years. The effects are significant among consumers with lower education and financial literacy. Individuals avoid overdrafts by making fewer low-balance debit transactions and cancelling automatic recurring withdrawals. The results raise new questions about consumer financial protection policy.

[We posit that consumer lenders shroud interest rates and market "low monthly payments" to price discriminate on "fuzzy math" or "payment/interest bias": consumers' pervasive tendency to underestimate borrowing costs when an interest rate is not disclosed. We test whether mandated disclosure changes lenders' ability to price discriminate using withinhousehold interactions between payment/interest bias and policy-induced variation in the strength of Truth-in-Lending Act (TILA) enforcement across lenders and time. Weak TILA enforcement substantially widens the gap between rates paid by more-biased and lessbiased borrowers. TILA compliance costs appear to increase interest rates overall, making the net effect on interest rates ambiguous.]

[Expanding access to commercial credit is a key ingredient of financial development strategies. There is less consensus on whether expanding access to consumer credit helps borrowers, particularly when loans are extended at high interest rates. Popular skepticism about "unproductive," "usurious" lending is fueled by research highlighting behavioral biases that may induce overborrowing. We estimate the impacts of expanding access to consumer credit at a 200% annual percentage rate (APR) using a field experiment and follow-up data collection. The randomly assigned marginal loans produced significant net benefits for borrowers across a wide range of outcomes. There is also some evidence that the loans were profitable.]

Information asymmetries are important in theory but difficult to identify in practice. We estimate the presence and importance of hidden information and hidden action problems in a consumer credit market using a new field experiment methodology. We randomized 58,000 direct mail offers to former clients of a major South African lender along three dimensions: (i) an initial “offer interest rate” featured on a direct mail solicitation; (ii) a “contract interest rate” that was revealed only after a borrower agreed to the initial offer rate; and (ii) a dynamic repayment incentive that was also a surprise and extended preferential pricing on future loans to borrowers who remained in good standing. These three randomizations, combined with complete knowledge of the lender's information set, permit identification of specific types of private information problems. Our setup distinguishes hidden information effects from selection on the offer rate (via unobservable risk and anticipated effort), from hidden action effects (via moral hazard in effort) induced by actual contract terms. We find strong evidence of moral hazard and weaker evidence of hidden information problems. A rough estimate suggests that perhaps 13% to 21% of default is due to moral hazard. Asymmetric information thus may help explain the prevalence of credit constraints even in a market that specializes in financing high-risk borrowers.

Exponential growth bias is the pervasive tendency to linearize exponential functions when assessing them intuitively. We show that exponential growth bias can explain two stylized facts in household finance: the tendency to underestimate an interest rate given other loan terms, and the tendency to underestimate a future value given other investment terms. Bias matters empirically: More-biased households borrow more, save less, favor shorter maturities, and use and benefit more from financial advice, conditional on a rich set of household characteristics. There is little evidence that our measure of exponential growth bias merely proxies for broader financial sophistication.

We examine how 17 behavioural biases relate to each other, to three standard measures of risk and time preferences, to cognitive skills, personality, and demographics, and to outcomes in household finance, well-being, and health. Most consumers in our nationally representative panel data exhibit multiple biases, with substantial cross-person heterogeneity. Biases are positively correlated within person, especially after adjusting for measurement error. From that correlation structure, we reduce our 20 bias and standard preference measures to four behavioural common factors. Each BCF reflects a group of related biases regarding beliefs, decision quality, discounting, or risk/uncertainty attitudes. The first two BCFs also strongly correlate with each other (positively) and cognitive skills (negatively). The first three BCFs and cognitive skills strongly correlate with various outcomes in the expected directions. Our results support processing-based models where basic limitations in cognition and/or attention produce multiple biases, and they have several other implications for theory and practice.