how general are time preferences eliciting good specific discount rates abstract this paper tests the commonly used assumption that people apply a single discount rate to the utility from different sources of consumption using survey data from uganda with both hypothetical and incentivized choices over different goods we elicit time preferences from about 2400 subjects we reject the null of equal discount rates across goods the average person in our sample is more impatient about sugar meat and starchy plantains than about money and a list of other goods we review the assumptions to recover discount rates from experimental choices for the case of good specific discounting consistently with the theoretical framework we find convergence in discount rates across goods for two groups expected to engage in or think about arbitraging the rewards traders and individuals with large quantities of the good at home as an application we evaluate empirically the conditions under which good specific discounting could predict a low asset poverty trap

discount rates and credit markets theory and evidence from rural india three models of credit markets 1 the permanent income model 2 upward sloping credit supply to individual borrowers and 3 constrained credit due to imperfect enforcement are tested using credit market data and an experimental study of individuals discount rates in south india the permanent income model is rejected by both the discount rate and the credit market data the discount rate data are consistent with either of the other two models while the credit market data are consistent with a combination of these two models other explanations are found to be insufficient to explain the results of this study

working over time dynamic inconsistency in real effort tasks experimental tests of dynamically inconsistent time preferences have largely relied on choices over time dated monetary rewards several recent studies have failed to nd the standard patterns of present bias however such monetary studies contain oftendiscussed confounds in this paper we sidestep these confounds and investigate choices over consumption real eort in a longitudinal experiment we pair this eort study with a companion monetary discounting study we conrm very limited time inconsistency in monetary choices however subjects show considerably more present bias in eort furthermore present bias in the allocation of work has predictive power for demand of a meaningfully binding commitment device therefore our ndings validate a key implication of models of dynamic inconsistency with corresponding policy implications

sustainability limited substitutability and non constant social discount rates abstract the paper shows how limited substitutability in consumption between different classes of goods affects the magnitude and time development of social discount rates it decomposes the discount rates into an absolute growth and a relative growth or substitutability effect the paper relates between good and intertemporal substitutability to the notions of weak and strong sustainability it analyzes under which circumstances low as opposed to high between good substitutability increases the weights given to long run environmental services

axiomatization and measurement of quasi hyperbolic discounting this article provides an axiomatic characterization of quasi hyperbolic discounting and a more general class of semi hyperbolic preferences we impose consistency restrictions directly on the intertemporal trade offs by relying on what we call annuity compensations our axiomatization leads naturally to an experimental design that disentangles discounting from the elasticity of intertemporal substitution in a pilot experiment we use the partial identification approach to estimate bounds for the distributions of discount factors in the subject pool consistent with previous studies we find evidence for both present and future bias jel codes c10 c99 d03 d90

inferring discount rates from time preference experiments abstract we observe that identification of the discount rate from experimental data requires an assumption about the consumption period the length of time over which a payment will be turned into utility providing consumption we show that the optimal consumption period is substantially longer than assumed in previous studies when the consumption period is allowed to take on more reasonable values the discount rates implied by experimental choices are unreasonably large and relatively insensitive to assumptions about utility curvature

the stability of measured time preferences abstract we use a panel dataset to test the stability of measured discount rates over time in response to changes in both macroeconomic events and household level labor market outcomes while discount rate measures are constructed to capture a rate of time preference our evidence is inconsistent with such an interpretation our results more closely align with the interpretation that standard methods to elicit discount rates reveal the market interest rate faced by an individual rather than their pure rate of time preference it follows directly from such an interpretation that factors which influence the interest rate at which a household can borrow and lend such as the inflation rate and household income ought to be correlated with the elicited discount rate a prediction supported by our data

discounting behaviour and the magnitude effect evidence from a field experiment in denmark we evaluate the claim that individuals exhibit a magnitude effect in their discounting behaviour where higher discount rates are inferred from choices made with lower principals all else being equal if the magnitude effect is quantitatively significant it is not appropriate to use one discount rate that is independent of the scale of the project for cost benefit analysis and capital budgeting using data from a field experiment in denmark we find statistically significant evidence of a magnitude effect that is much smaller than is claimed this evidence surfaces only if one controls for unobserved individual heterogeneity in the population

how general are risk preferences choices under uncertainty in different domains we analyze the extent to which individuals choices over five employer provided insurance coverage decisions and one 401 k investment decision exhibit systematic patterns as would be implied by a general utility component of risk preferences we provide evidence consistent with an important domain general component that operates across all insurance choices we find a considerably weaker relationship between one s insurance decisions and 401 k asset allocation although this relationship appears larger for more financially sophisticated individuals estimates from a stylized coverage choice model suggest that up to thirty percent of our sample makes choices that may be consistent across all six domains

present bias quasi hyperbolic discounting and fixed costs in this paper we elicit preferences for money time pairs via experimental techniques we estimate a general specification of discounting that nests exponential and hyperbolic discounting as well as various forms of present bias including quasi hyperbolic discounting our experimental data do not appear peculiar in any dimension in particular we find clear evidence for present bias as most of the previous literature however no evidence for quasi hyperbolic discounting is found and the data strongly favor instead a specification with a small present bias in the form of a fixed cost of the order of 4 on average across subjects with such a fixed cost the curvature of discounting is imprecisely estimated and exponential discounting is hardly rejected in this specification the present bias tends to vanish for economically relevant monetary rewards

expectational stability of sunspot equilibria in non convex economies we examine the stability under learning e stability of sunspot equilibria in non convex real business cycle models the production technology is cobbdouglas with externalities generated by factor inputs we establish that with a general utility function the well known benhabib farmer condition benhabib and farmer 1994 that the labor demand curve is upward sloping and steeper than the frisch labor supply curve is necessary for joint indeterminacy and e stability then with a separable utility function and allowing for negative externalities from capital inputs we discover large regions in parameter space corresponding to stable indeterminacy that is learnable sunspot equilibria these existence results overturn the conventional wisdom that sunspot equilibria in rbc type models are inherently unstable and provide concise closure to the stability puzzle of evans and mcgough 2005b

does africa need a rotten kin theorem experimental evidence from village economies this paper measures the economic impact of social pressure to share income with kin and neighbors in rural kenyan villages the authors conduct a lab experiment in which they randomly vary the observability of investment returns the goal is to test whether subjects reduce their income in order to keep it hidden the analysis finds that women adopt an investment strategy that conceals the size of their initial endowment in the experiment although that strategy reduces their expected earnings this effect is largest among women with relatives attending the experiment parameter estimates suggest that women behave as though they expect to be pressured to share four percent of their observable income with others and substantially more when close kin can observe income directly although this paper provides experimental evidence from a single african country observational studies suggest that similar pressure from kin may be prevalent in many rural areas throughout sub saharan africa

real time pricing of electricity for residential customers econometric analysis of an experiment under real time pricing a network operator sets the price level for a period according to a predefined scheme which depends on the state of demand and costs and announces this price shortly before the period begins the french state owned electric utility experimented with a six rate real time tariff which divides the year into three types of days and each day into two periods the number of days of each type is known in advance to the consumer but the type of any particular day is announced only at the end of the preceding day in order to evaluate the responsiveness of customers to this pricing option we estimate the frisch demand functions for daily electricity consumption derived from a simple dynamic model based on an additively separable intertemporal utility function as the marginal utility of expenditure which enters the frisch demands follows a known stochastic process the econometric model has a state space representation we can then apply the kalman filter to compute the log likelihood function associated with each consumer s time series of electricity consumption the main result of the analysis is that the real time tariff improves the welfare of a majority of consumers participating in the experiment

time discounting for primary and monetary rewards this paper reports a positive and statistically significant relation between short term discount rates elicited with a monetary and a primary reward chocolate the relation is most evident among people who like chocolate and are hungry this finding suggests that high short term discount rates are related to an underling individual trait consistent with models of presentbiased preferences

behavioral foundations of microcredit experimental and survey evidence from rural india microcredit is an innovative financial tool designed to reduce poverty and fix credit market imperfections we use experimental measures of time discounting and risk aversion for villagers in south india to highlight behavioral features of microcredit conditional on borrowing from any source women with present biased preferences are more likely than others to borrow through microcredit institutions microcredit contracts require loan repayments in regular fixed installments and they harness peer pressure to encourage discipline these innovations mirror mechanisms highlighted in behavioral approaches to saving suggesting that microcredit s popularity stems partly from modes of encouragement and self discipline absent in typical lending mechanisms

discounting behavior a reconsideration we re evaluate the theory experimental design and econometrics behind claims that individuals exhibit non constant discounting behavior theory points to the importance of controlling for the non linearity of the utility function of individuals since the discount rate is defined over time dated utility flows and not flows of money it also points to a menagerie of functional forms to characterize different types of non constant discounting behavior the implied experimental design calls for individuals to undertake several tasks to allow us to identify these models and to several treatments such as multiple horizons and the effect of allowing for a front end delay on earlier payments the implied econometrics calls for structural estimation of the theoretical models allowing for joint estimation of utility functions and discounting functions using data collected from a representative sample of 413 adult danes in 2009 we draw striking conclusions assuming an exponential discounting model we estimate discount rates to be 5 6 on average this is significantly lower than all previous estimates using controlled experiments we also find no evidence to support quasi hyperbolic discounting or fixed cost discounting and only modest evidence to support other specifications of non constant discounting furthermore the evidence for non constant discounting while statistically significant is not economically significant in terms of the size of the estimated discount rates we undertake extensive robustness checks on these findings including a detailed review of the previous comparable literature

temporal stability of time preferences abstract the preferences assumed to govern intertemporal trade offs are generally considered to be stable economic primitives though evidence on this stability is notably lacking we present evidence from a large field study conducted over two years with around 1 400 individuals using incentivized intertemporal choice experiments aggregate choice profiles and corresponding estimates of discount parameters are unchanged over the two years and individual correlations through time are high by existing standards however some individuals show signs of instability by linking experimental measures to administrative tax records we showthat identified instability is uncorrelated with both levels and changes in sociodemographic variables

risk attitudes and economic well being in latin america abstract a common conjecture in both the theoretical and policy literatures on development is that people remain poor because they are too impatient and risk averse to accumulate the resources needed to improve their well being the empirical literature however suggests that this conjecture is far from proven we sample more than 3000 participants drawn representatively from six latin american cities and find little correlation between baseline risk aversion and well being measured as an index of eight outcomes we do however find that measures of ambiguity aversion loss aversion and the willingness to take advantage of a risk pooling scheme all correlate with well being participants who are ambiguity averse loss averse and who react conservatively in the risk pooling condition all have significantly lower scores on our well being index these results are robust to the inclusion of a variety of important controls like human capital accumulation and access to credit

food and cash transfers evidence from colombia we study food engel curves among the poor population targeted by a conditional cash transfer programme in colombia after controlling for the endogeneity of total consumption and for the price variability across villages our estimates imply that an increase in consumption by 10 would lead to a decrease of 1 in the share of food however quasi experimental estimates of the impact of the programme show that the share of food increases this result is not inconsistent with the hypothesis that the programme could increase the bargaining power of women inducing a more than proportional increase in food consumption

spousal control and intra household decision making an experimental study in the philippines i elicit causal effects of spousal observability and communication on financial choices of married individuals in the philippines when choices are private men put money into their personal accounts when choices are observable men commit money to consumption for their own benefit when required to communicate men put money into their wives account these strong treatment effects on men but not women appear related more to control than to gender men whose wives control household savings respond more strongly to the treat ment and women whose husbands control savings exhibit the same response changes in information and communication interact with underlying control to produce mutable gender specific outcomes

demand estimation with expenditure measurement errors on the left and right hand side let x be total consumption expenditures measurement errors in consumer budget allocation models cause unusual problems because errors in the dependent variables consumption on individual goods contribute to errors in the regressor x empirically adequate budget share models like the aids translog and quadratic aids are linear or quadratic in log x it is shown that for these specifications two stage least squares fails to correct for the measurement error a simple technique for recovering consistent estimates from two stage least squares is provided along with an efficient generalized method of moments estimator the method is applied to u k fuel demand data copyright 1996 by mit press

hyperbolic discounting and the standard model eliciting discount functions abstract experiments on static intertemporal choice find evidence of particularly extreme impatience toward immediate rewards while this is often taken as support for hyperbolic discounting it could also arise because the most likely participants in experiments may be those with the most immediate need for money we conduct a calibration exercise and find that the extreme impatience observed in experiments can be accommodated by a standard exponential discounting model with no discounting and expectation of a small increase in the base consumption level the calibration uses existing estimates of curvature of utility

judging experimental evidence on dynamic inconsistency abstract this article briefly summarizes and judges recent experimental developments exploring the predictions of dynamically inconsistent models an opinion is provided as to how the literature ma

narrow bracketing and dominated choices an experiment by tversky and kahneman 1981 illustrates that people s tendency to evaluate risky decisions separately can lead them to choose combinations of choices that are first order stochastically dominated by other available combinations we investigate the generality of this effect both theoretically and experimentally we show that for any decisionmaker who does not have constant absolute risk averse preferences and who evaluates her decisions one by one there exists a simple pair of independent binary decisions where the decisionmaker will make a dominated combination of choices we also characterize as a function of a person s preferences the amount of money that she can lose due to a single mistake of this kind the theory is accompanied by both a real stakes laboratory experiment and a large sample survey from the general u s population replicating tversky and kahneman s original experiment where decisionmakers with prototypical prospect theory preferences will choose a dominated combination we find that 28 of the participants do so in the survey we ask the respondents about several hypothetical large stakes choices and find higher proportions of dominated choice combinations a statistical model that estimates preferences from the survey results is best fit by assuming people have utility functions that are close to prospect theory value functions and that about 83 of people bracket narrowly none of these results varies strongly with the personal characteristics of participants we also demonstrate directly that dominated choices are driven by narrow bracketing when we eliminate the possibility of narrow bracketing by using a combined presentation of the decisions the dominated choices are eliminated in the laboratory experiment and are greatly reduced in the survey

the demand for food and calories we investigate nutrition and expenditure in rural maharashtra in india we estimate that the elasticity of calorie consumption with respect to total expenditure is 0 3 0 5 a range that is in accord with conventional wisdom the elasticity declines only slowly with levels of living and is far from the value of zero suggested by a recent revisionist literature in these indian data the calories necessary for a day s activity cost less than 5 percent of the daily wage which makes it implausible that income is constrained by nutrition rather than the other way around

tying odysseus to the mast evidence from a commitment savings product in the philippines we designed a commitment savings product for a philippine bank and implemented it using a randomized control methodology the savings product was intended for individuals who want to commit now to restrict access to their savings and who were sophisticated enough to engage in such a mechanism we conducted a baseline survey on 1777 existing or former clients of a bank one month later we offered the commitment product to a randomly chosen subset of 710 clients 202 28 4 percent accepted the offer and opened the account in the baseline survey we asked hypothetical time discounting questions women who exhibited a lower discount rate for future relative to current trade offs and hence potentially have a preference for commitment were indeed significantly more likely to open the commitment savings account after twelve months average savings balances increased by 81 percentage points for those clients assigned to the treatment group relative to those assigned to the control group we conclude that the savings response represents a lasting change in savings and not merely a short term response to a new product

estimating time preferences from convex budgets experimentally elicited discount rates are frequently higher than what seems reasonable for economic decision making such high rates are often attributed to present biased discounting a well known bias of standard measurements is the assumption of linear consumption utility attempting to correct this bias using measures of risk aversion to identify concavity researchers find reasonable discounting but at the cost of exceptionally high utility function curvature we present a new methodology for identifying time preferences both discounting and curvature from simple allocation decisions we find reasonable levels of both discounting and curvature and surprisingly dynamically consistent time preferences jel c91 d12 d81 understanding and estimating time preferences is obviously of great importance to economists marketers and policy makers consumers decide how much to invest in savings education real estate and life insurance how much to diet exercise and smoke whether to marry when to have children and what to leave in their wills while there has been substantial research estimating time preferences using aggregate consumption data 1 the bulk of the effort has occurred in laboratory environments 2 among the many laboratory techniques employed recent studies have favored multiple price lists mpl with monetary payments 3 with mpls individuals are asked multiple times to choose between smaller payment amounts closer to the present and larger amounts further into the future the interest rate increases monotonically in a price list such that the point where an individual switches from preferring sooner payments to later payments carries interval

time consistency stationarity and time invariance a sequence of experiments documents static and dynamic preference reversals between sooner smaller and later larger rewards when the sooner reward could be immediate the theoretically motivated design permits separate identification of time consistent stationary a ndtime invariant choices at least half of the subjects are time consistent but only three quarters of them exhibit stationary choices about half of subjects with time inconsistent choices have stationary preferences these results chal lenge the view that present bias preferences are the main source of time inconsistent choices the past twenty years have seen a surge of interest in time inconsistent preferences mostly this has been motivated by psychological experiments and introspection that have suggested the existence of present bias a decision maker prefers smaller immediate reward to a larger delayed reward but when she is asked about her preferences between these two alternatives when both are equally shifted into the future her preferences are reversed although there is no inconsistency per se in her answers this behavior has been taken to suggest that when the decision maker will be asked to update her choices in the future she will generally deviate from her ex ante plans our goal in the present study is to perform a dynamic preference reversal experiment as such one is required to extend the standard framework of pref erences over temporal payments to a dated collection of such preferences this extension allows us to formally define three distinct properties stationarity im plies that ranking of temporal payments depends only on the time distance and payment distance between the alternatives time invariance assumes that the decision maker evaluates each temporal payment relative to the evaluation pe

quadratic engel curves and consumer demand this paper presents a model of consumer demand that is consistent with the observed expenditure patterns of individual consumers in a long time series of expenditure surveys and is also able to provide a detailed welfare analysis of shifts in relative prices a nonparametric analysis of consumer expenditure patterns suggests that engel curves require quadratic terms in the logarithm of expenditure while popular models of demand such as the translog or the almost ideal demand systems do allow flexible price responses within a theoretically coherent structure they have expenditure share engel curves that are linear in the logarithm of total expenditure we derive the complete class of integrable quadratic logarithmic expenditure share systems a specification from this class is estimated on a large pooled data set of u k households models that fail to account for engel curvature are found ro generate important distortions in the patterns of welfare losses associated with a tax increase