Habit Formation in an Interdependent World Economy

In a two-country world economy, consumption-habit dynamics in one country are affected, due to endogenous interest rate adjustments, by the other country's habits and preferences. External indebtedness depends crucially on international differences in habit-adjusted net output less habitual living standard. Interest rate adjustments enlarge the consumption impact of an income shock. Consistently with the empirical facts, the habit parameter of a large country, therefore, would be underestimated, and the current account volatility overestimated, if estimated using a small-country model. An increase in fiscal spending in one country can benefit the country and harm the neighbor due to intertemporal terms-of-trade effects.

Generalized Hyperbolic Discounting, Borrowing Aversion, and Debt Holding

Analysis of an original, broad, internet-based survey reveals that debt holding is related to three aspects of time discounting: (i) present bias, measured by the degree of declining impatience in the generalized hyperbolic discount function; (ii) borrowing aversion, captured by a sign effect - discounting future losses at a lower rate than future gains; and (iii) impatience, measured by the overall discount rate. Present-biased respondents are classified as naĩve if their answers reveal them to be time-inconsistent procrastinators, and classified as sophisticated otherwise. Naĩve respondents with more steeply declining impatience are more likely to be debtors, and are likely to have larger amounts of debt, whereas sophisticates display only insignificant positive association between declining impatience and debt holding. Responses indicative of a sign effect are negatively associated with debt holding. The marginal effect on debt of such a sign effect is larger in magnitude than the effect of one standard deviation increases both in declining impatience and in impatience. Survey responses indicative of high or declining impatience are associated with high debt-to-income ratios, borrowing on credit cards, and the experiences of having borrowed unsecured consumer loans, of having engaged in debt-restructuring, or of having declared personal bankruptcy.

Time Discounting and Smoking Behavior under Tax Hikes

By combining our broad panel survey of Japanese adults from 2005 to 2008 and actual cigarette tax data, we investigate how smoking behavior including responses to tax hikes depends on time discounting and its biases, such as hyperbolic discounting and the sign effect. Cigarette consumption displays significantly positive correlations with discount rates and the procrastinating tendency, and negative correlations with the sign effect. Hyperbolic, procrastinating, andna�ve respondents decrease their after-tax-hike cigarette consumption more than the others, implying that, irrespective of the preannouncement of a future tax hike, they postpone smoking moderation until the tax hike actually takes place. Finally, the government's revenue from cigarette tax peaks at a JPY 29.92 (around USD 0.28 using the conversion rate [107.16] in February 2008) higher tax per cigarette than the present actual level.

Fat Debtors: Time Discounting, Its Anomalies, and Body Mass Index

In view of the finding that debtors are likely to be more obese than nondebtors, we investigate whether interpersonal differences in body mass are, as in the case of debt behavior, related to those in time discounting and time discounting anomalies. The effects of time discounting on body massindex (BMI) and the probabilities of being obese, severely obese, and underweightare detected by incorporating three properties of intertemporal preferences: (i) impatience, measured by the level of the respondentsf discountrate; (ii) hyperbolic discounting, where discount rates for the discountingof immediate future payoffs are higher than those of distant future payoffs; and (iii) the sign effect, wherein future negative payoffs are discounted ata lower rate than are future positive payoffs. We also find that body mass is non-monotonically correlated with age, income, and working hours. As a policy implication, body mass can potentially be controlled by changing the intertemporal structure of medical care costs.

Habit Formation in an Interdependent World Economy

ISER discussion paperSeptember 2004 Revised July 200