







Abstract. We explore dynamics of limited attention in the $35 billion market for checking overdrafts, using survey content as shocks to the salience of ove
Unshrouding: Evidence from Bank Overdrafts in Turkey
ABSTRACT Lower prices produce higher demand… or do they? A bank's direct marketing to holders of “free” checking accounts shows that a large discount on 60% APR overdrafts reduces overdraft usage, especially when bundled with a discount on debit card or autodebit transactions. In contrast, messages mentioning overdraft availability without mentioning price increase usage. Neither change persists long after the messages stop. These results do not square easily with classical models of consumer choice and firm competition. Instead, they support behavioral models where consumers underestimate and are inattentive to overdraft costs, and firms respond by shrouding overdraft prices in equilibrium.

Analyzing Bank Overdraft Fees with Big Data
In 2012, consumers paid $32 billion in overdraft fees, representing the single largest source of revenue for banks from demand deposit accounts during this period. Owing to consumer attrition caused by overdraft fees and potential government regulations to reform these fees, financial institutions have become motivated to investigate their overdraft fee structures. Banks need to balance the revenue generated from overdraft fees with consumer dissatisfaction and potential churn caused by these fees. However, no empirical research has been conducted to explain consumer responses to overdraft fees or to evaluate alternative pricing strategies associated with these fees. In this research, we propose a dynamic structural model with consumer monitoring costs and dissatisfaction associated with overdraft fees. We apply the model to an enterprise-level data set of more than 500,000 accounts with a history of 450 days, providing a total of 200 million transactions. We find that consumers heavily discount the future and potentially overdraw because of impulsive spending. However, we also find that high monitoring costs hinder consumers’ effort to track their balance accurately; consequently, consumers may overdraw because of rational inattention. The large data set is necessary because of the infrequent nature of overdrafts; however, it also engenders computational challenges, which we address by using parallel computing techniques. Our policy simulations show that alternative pricing strategies may increase bank revenue and improve consumer welfare. Fixed bill schedules and overdraft waiver programs may also enhance social welfare. This paper explains consumer responses to overdraft fees and evaluates alternative pricing strategies associated with these fees. The online appendices are available at https://doi.org/10.1287/mksc.2018.1106 .

Time to Act: A Field Experiment on Overdraft Alerts
Despite the growth of digital banking and the rapidly expanding offering of money management applications, a substantial proportion of banking customers still i
Using AI and Behavioral Finance to Cope with Limited Attention and Reduce Overdraft Fees
<p><span>We test how effective a human-algorithm interaction is at stopping users from overdrawing their bank accounts. We use a randomized field experiment and
Do Customers Learn from Experience? Evidence from Retail Banking
We study customers' adoption and subsequent switching decisions with regard to a menu of three-part tariff plans offered by a commercial bank. Using a rich panel data set covering 70,510 fee-based checking accounts over 30 months, before and after the introduction of the plans, we find that most customers adopt non-cost-minimizing plans, preferring plans with large monthly allowances and high fixed payments. Furthermore, after adoption, customers who exceed their allowances and consequently pay overage fees are more likely to switch to plans with larger allowances than customers who do not experience such fees. Notably, after switching, these overage-paying customers pay higher monthly payments than before. In contrast, switching customers who did not pay overage payments before switching pay less after switching. Our findings, unlike those of previous research on experience-based learning, suggest that the behavior of experienced customers does not converge to the predictions of neoclassical models. We propose that “overage aversion,” which is closely related to loss aversion and mental accounting, is the most plausible explanation for our findings. This paper was accepted by John List, behavioral economics.

The Ostrich in Us: Selective Attention to Personal Finances
Abstract We analyze attention to personal finances using a high-frequency panel of bank data, including information on logins. We document a number of robust patterns. Relative to their personal histories, individuals pay more attention when holding more cash and liquidity and when receiving income. In contrast, attention decreases discretely as bank account balances go from positive to negative and then decreases further as overdraft debt increases. We conclude that Ostrich effects in a personal finance context, i.e., the avoidance of obtaining information on everyday personal finances, is a widespread phenomenon and explore a number of explanations for our findings.

Sending Out an SMS: Automatic Enrollment Experiments for Overdraft Alerts
ABSTRACT At‐scale field experiments at major U.K. banks show that automatic enrollment into “just‐in‐time” text alerts reduces unarranged overdraft and unpaid item charges 17% to 19% and arranged overdraft charges 4% to 8%, implying annual market‐wide savings of £170 million to £240 million. Incremental benefits from “early‐warning” alerts are statistically insignificant, although economically significant effects are not ruled out. Prior to the experiments, over half of overdrafts could have been avoided by using lower‐cost liquidity available in savings and credit card accounts. Alerts help consumers achieve less than half of these potential savings.

Side Effects of Nudging: Evidence from a Randomized Intervention in the Credit Card Market
Abstract This paper studies the direct and indirect effects of nudging, by means of a field experiment with a financial management platform in Brazil. Reminders for upcoming credit card payments reduced credit card late-payment fees by 14%, but increased overdraft fees in checking accounts by 9%. The unintended effect is concentrated in users with a history of overdraft use. These users experienced a net increase of 5% in total fees, while the rest experienced savings of 15%. The results provide clear insights for nudge design: like any policy action, nudges can have side effects, and one size may not fit all.

Consumption Response to Credit Expansions: Evidence from Experimental Assignment of 45,307 Credit Lines
In a field experiment that constructs a randomized credit limit shock, participants borrow to spend 11 cents on the dollar in the first quarter and 28 cents by the third year. Effects extend to those far from the limit, those who had the new limits as available credit, and those with a liquid asset buffer. In the short-run, flexible and installment contracts are used in tandem, with unconstrained using installments more. Long-run borrowing is predominantly using installments. Near limits, participants borrow when credit expands but save out of constraints when limits are tight. Findings support a buffer-stock interpretation emphasizing precautionary saving.
Borrowing on the Wrong Credit Card? Evidence from Mexico
We establish new facts about the way consumers allocate debt among their credit cards using data for a representative sample of cardholders in Mexico. We find that relative prices are weak predictors of the allocation of debt, purchases, and payments. Consumers allocate a large fraction of their debt to high-interest cards, incurring a cost of 31 percent above the minimum. Using an experiment, we find that consumers do not substitute in the price margin, although they respond to salient temporary low-interest offers. We conclude that limited attention and mental accounting best rationalize our results and discuss implications for the market.
What Do Consumers Really Pay on Their Checking and Credit Card Accounts? Explicit, Implicit, and Avoidable Costs
(May 2009)
Do Nudges Reduce Borrowing and Consumer Confusion in the Credit Card Market?
We study nudges that turn out to have precise null effects in reducing long‐run credit card debt. We test nudges across two field experiments covering 183,441 UK cardholders. Our first experiment studies nudges added to monthly credit card statements. Our second experiment studies letters and email nudges (separate from monthly statements) sent to cardholders who signed up to automatically pay the minimum required payment. In a follow‐up survey to our second experiment, we find that 96% of respondents underestimate the time it would take to fully repay a debt if the cardholder made only the minimum required payment. The nudges reduce this confusion, but underestimation remains overwhelmingly common.

Timing to the Statement: Understanding Fluctuations in Consumer Credit Use
We show that consumers spend 15% more per day in the first week following the receipt of a credit card statement than in the days just prior to the statement. This increase in spending includes both an increase in the likelihood that they use the credit card in the first weeks following their statement and an increase in transaction amount on days they use the credit card. In contrast to the effect on credit card spending, debit card spending is unaffected by credit card statement issuance, suggesting that consumers are not simply switching among modes of payment. Our estimates are based on exogenous variation from bank-assigned statement dates. We propose and test several alternative explanations to this spending puzzle: optimization of the free float, salience effect of the credit card statement, mental accounting, liquidity constraints, and automatic payments. We find that the consumers most apt to spend early in the credit card cycle tend to be those who do not revolve balances and are not close to their credit limit. Thus, this paper documents a puzzle with mixed support for several alternative explanations. This paper was accepted by David Simchi-Levi, finance.

The Effects of Prior Spending on Future Spending Decisions: The Role of Acquisition Liabilities and Payments
Research in mental accounting shows that prior spending influences a consumer's decision to make a new spending decision (Heath and Soll 1996, Soman 2001). In particular, greater spending in a particular category reduces the likelihood of further spending in that category. In the present research, we decompose “spending” into two distinct episodes—the acquisition liability episode during which a purchase is made accompanied by a commitment to pay (e.g., using a credit card) and the payment episode during which the consumer's wealth actually gets depleted (e.g., paying the credit card bill). Using a controlled laboratory experiment and real world data from a group of consumers, we replicate earlier findings that prior spending influences a pending spending decision, but also show that the location of both the acquisition liability episode and the payment episode play a role. Our results contribute to an understanding of the dynamic mental accounting of acquisition liability and actual outflows.
Purchase Justifiability Drives Payment Choice: Consumers Pay with Card to Remember and Cash to Forget
AbstractAlthough consumers often have multiple payment methods at their fingertips, such as cash and credit/debit cards, prior research is silent on how consumers choose between them. We home in on a key element of purchase—purchase justifiability—that affects how consumers choose to pay. Analysis of 118,042 real-world purchases and six experiments reveals that when consumers are motivated to forget (vs. remember) a purchase because they see it as difficult (vs. easy) to justify, they have an increased preference to pay with cash (vs. card) because cards create a “paper/electronic trail” that aids memory retrieval. These payment preferences are strongest among consumers most likely to recall/track their card spending, and manifest only when card expenses are trackable. We reconcile our results with the classic effect of payment method on pain of paying and discuss implications for merchants and for financial institutions designing payment methods of the future.

Disclosing the costs of co-holding liquid assets and high-interest debt has limited impact on behavior
Abstract Why do consumers simultaneously maintain low-yield liquid assets and high-interest revolving debt? This behavior, known as ``co-holding,'' affects 23\% of credit card users in our sample from a major international bank and costs the typical co-holder hundreds of dollars annually in unnecessary interest charges. Our analysis of 38 months of detailed banking records reveals that co-holding is remarkably persistent, with typical co-holders maintaining this behavior for most months observed. Our analysis also reveals that co-holding is not a static financial position: co-holders regularly deposit and withdraw from asset accounts while simultaneously making new credit card purchases. To test whether co-holding could be addressed through information disclosure, we conducted a large-scale field experiment (n = 125,328), providing clear information about co-holding behavior and its costs. Customers received targeted messages through their bank's mobile app, where they could easily transfer money from assets to pay down debt. Despite sufficient power to detect economically small effects, we found no meaningful changes in debt repayment amount, though customers did respond in other ways---making more frequent repayments and paying above required minimums. These results challenge explanations based on limited attention or information gaps and suggest that simple information disclosure, even when carefully designed and delivered through trusted channels, may not effectively address costly financial behaviors.
