„Paying Not to Go to the Gym“ ist der Titel einer Studie von Stefano Della Vigna und Ulrike Malmendier, die damals an den Universitäten Berkeley und Stanford forschten - auf Deutsch: „Zahlen, um nicht ins Fitnessstudio zu gehen.“ Den Titel haben die beiden Forscher mit Bedacht gewählt. Denn sie haben herausgefunden: 17 Dollar zahlten die Mitglieder amerikanischer Studios im Durchschnitt pro Besuch. Hätten sie einzeln abgerechnet, wären sie mit 10 Dollar pro Besuch davongekommen. Aber so denkt ja keiner. Jeder nimmt sich vor, regelmäßig ins Fitnessstudio zu gehen, und bringt die Disziplin dafür hinterher trotzdem nicht auf. Nur: Wenn jeder Besuch im Fitnessstudio Geld kosten würde, würden wir noch seltener zum Training gehen.

How do consumers choose from a menu of contracts? We analyze a novel data set from three US health clubs with information on both the contractual choice and the dayto- day attendance decisions of 7,978 members over three years. The observed consumer behavior is difficult to reconcile with standard preferences and beliefs. First, members who choose a contract with a flat monthly fee of over $70 attend on average 4.8 times per month. They pay a price per expected visit of more than $17, even though they could pay $10 per visit using a 10—visit pass. On average, these users forgo savings of $700 during their membership. Second, consumers who choose a monthly contract are 18 percent more likely to stay enrolled beyond one year than users committing for a year. This is surprising because monthly members pay higher fees for the option to cancel each month. We also document cancellation delays and attendance expectations, among other findings. Leading explanations for our findings are overconfidence about future efficiency or about future self-control. Overconfident agents overestimate attendance as well as the cancellation probability of automatically-renewed contracts. Our results suggest that making inferences from observed contract choice under the rational expectation hypothesis can lead to biases in the estimation of consumer preferences.