Stefano DellaVigna

Contract Design and Self-Control: Theory and Evidence

How do rational firms respond to consumer biases? In this paper we analyze the profit-maximizing contract design of firms if consumers have time-inconsistent preferences and are partially naive about it. We consider markets for two types of goods: goods with immediate costs and delayed benefits (investment goods) such as health club attendance, and goods with immediate benefits and delayed costs (leisure goods) such as credit card-financed consumption. We establish three features of the profit-maximizing contract design with partially naive time-inconsistent consumers. First, firms price investment goods below marginal cost. Second, firms price leisure goods above marginal cost. Third, for all types of goods firms introduce switching costs and charge back-loaded fees. The contractual design targets consumer misperception of future consumption and underestimation of the renewal probability. The predictions of the theory match the empirical contract design in the credit card, gambling, health club, life insurance, mail order, mobile phone, and vacation time-sharing industries. We also show that time inconsistency has adverse effects on consumer welfare only if consumers are naive.

The Effect of Fast Food Restaurants on Obesity and Weight Gain

We investigate how changes in the supply of fast food restaurants affect weight outcomes of 3 million children and 3 million pregnant women. Among ninth graders, a fast food restaurant within 0.1 miles of a school results in a 5.2 percent increase in obesity rates. Among pregnant women, a fast-food restaurant within 0.5 miles of residence results in a 1.6 percent increase in the probability of gaining over 20 kilos. The implied effects on caloric intake are one order of magnitude larger for children than for mothers, consistent with smaller travel cost for adults. Non-fast food restaurants and future fast-food restaurants are uncorrelated with weight outcomes. (JEL I12, J13, J16, L83)

Overestimating Self-Control: Evidence from the Health Club Industry

Experimental evidence suggests that people make time-inconsistent choices and display overconfidence about positive personal attributes. Do these features affect consumer behavior in the market? To address this question we use a new panel data set from three US health clubs with information on the contract choices and the day-to-day attendance decisions of 7,978 health club members over three years. Members who choose a contract with a flat monthly fee of over

Investor Inattention, Firm Reaction, and Friday Earnings Announcements

70 attend on average 4.8 times per month. They pay a price per expected visit of more than

Job Search and Hyperbolic Discounting

17, even though a

Economic and Social Impacts of the Media

10-per-visit fee is also available. On average, these users forgo savings of

Strategic Release of Information on Friday: Evidence from Earnings Announcements

700 during their membership. We review many aspects of the consumer behavior, including the interval between last attendance and contract termination, the survival probability, and the correlation between different consumption choices. The empirical results are diffcult to reconcile with the standard assumption of time-consistent preferences and rational expectations. A model of time-inconsistent agents with overconfidence about future time inconsistency explains the findings. The agents overestimate the future attendance and delay contract cancellation whenever renewal is automatic.

Learning to Make Risk Neutral Choices in a Symmetric World

Do firms release news strategically in response to investor inattention? We consider news about earnings and analyze the response of returns to announcements on Friday and other weekdays. Friday announcements have less immediate and more delayed stock return response. The delayed response as a percentage of the total response is 60 percent on Friday and 40 percent on other weekdays. In addition, abnormal trading volume around announcement day is 10 percent lower for Friday announcements. These findings suggest that weekends distract investor attention temporarily. They support explanations of post-earning announcement drift based on underreaction to information caused by limited attention. We also document that firms release worse announcements on Friday. Friday announcements are associated with a 45 percent higher probability of a negative earnings surprise and a 50 basis points lower abnormal return. The firm-based evidence of strategic news release corroborates the investor-based evidence of inattention on Friday. The results for stock returns, volume, and strategic behavior support the hypothesis of limited attention.

Consumers Who Care

We propose a simple test of hyperbolic versus exponential preferences in a job search model. More impatient workers search less intensively but also accept lower wages. If agents have hyperbolic preferences, the search effect dominates, so increases in impatience lead to lower exit rates from unemployment. The opposite is generally true for agents with exponential preferences: more impatient workers exit unemployment sooner. Using two large longitudinal data sets, we find that various measures of impatience are negatively correlated with the exit rate from unemployment, contrary to the predictions of the exponential discounting model. A human capital story does not explain the results either. The empirical findings support the hyperbolic model.

Uniform Pricing in US Retail Chains

In this survey, we review the literature on the impact of exposure to the media. We cast a wide net and cover media impacts on education, family choices, labor and migration decisions, environmental choices, health, crime, public economics, attitudes, consumption and savings, and development economics. We stress five themes. First, the demand for entertainment plays a key role, with the economic impacts emerging largely as by-products. Second, to understand the media effects one cannot just focus on the direct effect of exposure but one needs to take into account the crowding-out of alternative activities (substitution effect). Third, the sources of identification play a critical role in determining what is known: credible estimates of short- and long run effects are available for some topics and some media but not for others. Fourth, most of the evidence on social and economic impacts is for exposure to the entertainment media such as television, as opposed to the printed press. Fifth, for the policy impacts both the substitution effect of media exposure and the demand for entertainment play an important role.