Analysis of an original Internet-based survey reveals that debt holding is related to time discounting through: (i) present bias, measured by the degree of declining impatience in the generalized hyperbolic discount function; (ii) borrowing aversion, captured by a sign effect in that future losses are discounted at lower rates than future gains; and (iii) impatience, measured by the overall discount rate. Hyperbolic respondents are classified naïve if their answers reveal them to be time-inconsistent procrastinators, and otherwise sophisticated. Naïve respondents with more steeply declining impatience are more likely to be debtors. The sign effect relates negatively to borrowing. Survey responses indicative of high or declining impatience are associated with credit card borrowing and other overborrowing indicators. JEL Classification Numbers: D91, D14, D03.bs_bs_banner First, we specify the discount function in the form of a "generalized hyperbolic discount function" (Loewenstein and Prelec, 1992), which is characterized by two parameters. One parameter (α) indicates the degree of hyperbolic deviation from exponential discounting, and the other (γ) determines the intercept. We adduce the two parameters for each individual from responses to hypothetical questions regarding immediate future choices and distant future choices. Each individual's α value measures his or her degree of declining impatience. We find that this measure is associated with debt behaviour in the way predicted. The inferred individual values of parameter γ are combined with other discount rates to construct each individual's degree of impatience.Second, we distinguish the naïve, who do not expect that as time passes their impatience for given points in the future is going to rise, and the sophisticated, who correctly anticipate the future incidence of their own preference reversals and behave consistently with what their future impatient "selves" would do. Theory predicts that hyperbolically discounting naïve consumers display time-inconsistent overborrowing, whereas sophisticated people may somehow forestall their own undesirable inclination to overborrow (e.g. Phelps and Pollack, 1968;O'Donoghue and Rabin, 1999;Heidhues and Köszegi, 2010). To examine the validity of the theoretical predictions, we asked respondents two questions regarding their behavioural tendencies. One is how likely they were to procrastinate in doing onerous homework assignments during school vacations during childhood. The other is how late did they plan to do the particular homework assignments. Using the response data, we divide hyperbolic respondents into naïve ones, who self-reported unplanned procrastination, and sophisticated ones, who did not. We show how the effect of hyperbolic discounting on debt holdings depends on whether the respondent is naïve or sophisticated.As the third novelty, we examine the association between time discounting and inclination toward overborrowing, which is revealed by borrowing on credit cards, and the experiences of having unsecured...