







ABSTRACT Using an experiment in which 3.1 million bank customers were encouraged to save, we explore the mechanisms behind coholding liquid savings and credit card debt. Theoretically, we show that the joint responses of spending, saving, and borrowing to the nudge differ across economic models of coholding. Using machine learning techniques, we find that the most responsive individuals reduce spending and increase savings by 4.9% (206 USD PPP per month) while their credit card debt remains unchanged. These individuals' marginal responses to the nudge are consistent with our model of coholding for the purpose of self‐ or partner‐control.
Does Saving Cause Borrowing? Implications for the Co-Holding Puzzle
Using an experiment in which 3.1 million bank customers were encouraged to save, we explore the mechanisms behind co-holding liquid savings and credit card debt. Theoretically, we first show that the joint responses of spending, saving, and borrowing to the nudge differ for different economic models of co-holding. Using machine learning techniques, we then find that the most responsive individuals reduce spending and increase their savings by 4.9% (206 USD PPP per month) while their credit card debt remains unchanged. For them, the marginal responses to the nudge are consistent with our model of co-holding for the purpose of self- or partner control.

The Coholding Puzzle: New Evidence from Transaction-Level Data
Abstract Why do individuals pay debt interest when they could use their savings to pay down the debt? We explore why individuals “cohold” debt and savings using detailed and highly disaggregated daily-level data on household finances. We find that coholding mostly occurs in short spells within the month and the level of coholding is typically modest. Periods of coholding are not associated with shocks at the individual level. We show that mental accounting has a role to play in explaining coholding, in particular how individuals allocate different categories of expenditure to accounts in credit and debit.

The Co-holding Puzzle: New Evidence from Transaction-Level Data
Using detailed and highly disaggregated data on household finances, we examine the<br>tendency of consumers to “co-hold” savings and debt simultaneously. The di
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.

Co-holding behaviour: unlocking the puzzle
This article seeks to explain why households decide to simultaneously hold both credit and savings products. Beyond the arguments of ignorance or behavioural biases commonly used in the literature,...

Intra-Household Frictions, Anchoring, and the Credit Card Debt Puzzle
Abstract I study how intra-household frictions and anchoring contribute to the credit card debt puzzle, the co-holding of high-cost debt, and low-yield liquid assets. First, I find couples co-hold 42% more as units than as individuals relative to income. Moreover, in a natural experiment, couples do not cooperate to reduce high-cost debt, suggesting that intra-household frictions contribute to co-holding. Second, I find individuals who regularly make credit card debt payments equal to or near the minimum account for 59% of individual co-holding. The evidence suggests anchoring to the minimum payment contributes to co-holding via these low payments.

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.
Knowing When to Spend: Unintended Financial Consequences of Earmarking to Encourage Savings
Maintaining savings is an important financial goal. Yet there are times when savings should be spent, such as when people face unavoidable costs, and spending their savings allows them to avoid high interest rate debt. Existing behavioral research has focused on consumer decisions between savings and discretionary spending and has proposed interventions to promote savings in these contexts. However, when spending is not discretionary, such interventions could risk exacerbating a pattern found in economic research in which people borrow high interest rate debt while maintaining savings that earn low levels of interest. To examine how mental accounting interacts with considerations of personal responsibility and guilt to contribute to this pattern, this article explores whether people spend their savings when they need money most: during emergencies. Six studies reveal that people's tendency to preserve savings by borrowing from a high interest rate credit option varies as a function of the savings’ intended use. Paradoxically, people are most likely to turn to high interest rate credit with the belief that doing so is the responsible option.

The Co-Holding Puzzle: New Evidence from Transaction-Level Data
The tendency of consumers to hold low-yield liquid savings while simultaneously holding high-cost unsecured credit on revolving credit lines is a long standing
Overconfidence and the Credit Card Debt Puzzle
This article investigates the credit card debt puzzle. Simultaneously holding credit card debt and liquid assets is puzzling given the sizeable difference between interest rates of debt and assets. However, this behavior is common—about 31% of households in the 2016 Survey of Consumer Finances. The cost of co-holding may be justified if consumers anticipate future restrictions in credit or if they need to maintain liquidity. Other existing explanations for co-holding include impulsive spending and low financial literacy. This research reveals a new explanation for the credit card debt puzzle: consumers’ overconfidence of their financial knowledge. Using a Coarsened Exact Matching method, we found that overconfident consumers were 20%–40% more likely to co-hold credit card debt and liquid assets.
Cash versus Debit Card: The Role of Budget Control
Due to the financial crisis, an increasing number of households face financial problems. This may lead to an increasing need for monitoring spending and budgets. We demonstrate that both cash and the debit card are perceived as helpful in this respect. We show that, on average, consumers responsible for financial decision making within a household find cash and the debit card equally helpful for monitoring their household finances. Individuals differ in major respects, however. In particular, low earners and the liquidity‐constrained prefer cash as a budgeting tool. Finally, we present evidence that at an aggregated level, such preferences strongly affect consumer payment behavior. These findings suggest that the substitution of cash by cards may slow down because of the financial crisis.

Payment Rewards and Credit Card Debt: Experimental Evidence
We report on a controlled laboratory experiment in which participants make consumption, saving, and credit card repayment decisions when credit card purchases e
Balancing Savings and Debt: Findings from an Online Experiment
Many consumers have savings and debt at the same time, and so are faced with a trade-off: how much debt to pay down versus how much savings to retain. This brie
Leave Home without it? The Effects of Credit Card Debt and Available Credit on Spending
This research examines how credit card debt affects consumer spending. In five experimental and field studies, the authors demonstrate that outstanding credit card debt increases spending for consumers with high self-control. They also show that this effect can be eliminated by increasing the available credit on the credit card. Thus, when the available credit is low, consumers with greater self-control increase spending, but when the available credit is high, they reduce spending. The results extend the literature on goal violation and self-control and offer insights into consumer decision making and consumption patterns under conditions of debt.

Keeping Cash and Revolving Debt: How Consumers' Preference for Spending on Debit versus Credit Influences their Decision to Co-Hold
This paper investigates "co-holding'"–whereby consumers simultaneously maintain low-yield liquid assets and high-interest revolving debt–through the l
When Motivation is against Debtors' Best Interest: The Illusion of Goal Progress in Credit Card Debt Repayment
The authors explore the illusion of goal progress by consumers who own multiple credit cards and pay off their debt balances to facilitate the achievement of their subgoal rather than the superordinate goal of being debt-free. The first experiment shows that debtors use their savings toward the credit card debt they can pay off entirely or substantially, even if it is associated with the smallest balance and the lowest annual percentage rate rather than toward the debt with the highest annual percentage rate. The second experiment reveals that when the income available to pay down the debt is in the form of effortless money (i.e., windfall or reward money) as opposed to hard-earned savings, the tendency to allocate money toward the smallest credit card debt is exacerbated. However, people tend to pay their debt more rationally when the number of debt accounts increases. Finally, the third experiment shows that credit card debt repayment decisions depend on the nature of the debt (hedonic vs. utilitarian) and the timing of consumption benefits (past vs. future). The article concludes with a discussion of managerial and public policy implications.
