Policy Effects in Hyperbolic vs. Exponential Models of Consumption and Retirement

This paper constructs a structural retirement model with hyperbolic preferences and uses it to estimate the effect of several potential Social Security policy changes. Estimated effects of policies are compared using two models, one with hyperbolic preferences and one with standard exponential preferences. Sophisticated hyperbolic discounters may accumulate substantial amounts of wealth for retirement. We find it is frequently difficult to distinguish empirically between models with the two types of preferences on the basis of asset accumulation paths or consumption paths around the period of retirement. Simulations suggest that, despite the much higher initial time preference rate, individuals with hyperbolic preferences may actually value a real annuity more than individuals with exponential preferences who have accumulated roughly equal amounts of assets. This appears to be especially true for individuals with relatively high time preference rates or who have low assets for whatever reason. This affects the tradeoff between current benefits and future benefits on which many of the retirement incentives of the Social Security system rest.Simulations involving increasing the early entitlement age and increasing the delayed retirement credit do not show a great deal of difference whether exponential or hyperbolic preferences are used, but simulations for eliminating the earnings test show a non-trivially greater effect when exponential preferences are used.     

Quasi-hyperbolic discounting and social security systems

Hyperbolic discounting has become a common assumption for modeling bounded rationality with respect to individual savings decisions. We examine the effects of hyperbolic discounting on the comparison of alternative social security systems. We show that this form of bounded rationality breaks the equivalence between funded and pay-as-you-go (PAYG) systems established in Sheshinski and Weiss [Sheshinski, E., Weiss, Y., 1981. Uncertainty and optimal social security. Quarterly Journal of Economics 95, 189-206]. Intergenerational transfers within a PAYG economy are usually secured by the social security system and independent of longevity, whereas this is not the case for the funded economy. The savings level under hyperbolic discounting is lower than under exponential discounting [Laibson et al., 1998], but the ratio between the savings level under hyperbolic discounting within a funded economy and a PAYG economy depends on the effectiveness of the commitment devices. It is shown that if individuals are hyperbolic discounters, then in a PAYG economy any change in the mandated level of intergenerational transfers is neutralized by individuals’ voluntary bequests. This does not apply to a funded system.     

Hyperbolic Discounting,Borrowing Aversion and Debt Holding

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.     

Patience auctions: the impact of time vs. money bidding on elicited discount rates

We introduce, test, and compare two auction-based methods for eliciting discount rates. In these “patience auctions”, participants bid the smallest future sum they would prefer -or- the longest time they would wait for a reward, rather than receive a smaller, immediate payoff. The most patient bidder receives the delayed reward; all others receive the immediate payoff. These auctions allow us to compare discounting when participants’ attention is focused on the temporal versus monetary dimension of delayed rewards. We find that the estimated parameters in the three most commonly used discount functions (exponential, hyperbolic, and quasi-hyperbolic) differ across these two bidding methods (time-bids vs. money-bids). Specifically, our participants tend to show more impatience under time-bids. Furthermore, we find that people are more likely to exhibit exponential (as opposed to hyperbolic) discounting and exhibit less present bias under time-bids, compared to money-bids. To our knowledge, this paper is the first to directly compare time versus money preference elicitations, within the same subjects, using an incentive-compatible mechanism.     

Hyperbolic discounting and uniform savings floors

Previous research suggests that, in partial equilibrium, individuals whose decision-making exhibits a present-bias – such as hyperbolic discounters who tend to over-consume – will be in favor of having a floor imposed on their savings. In this paper, I show it is quite difficult for the introduction of a savings floor to be Pareto improving in general equilibrium. Indeed, a necessary condition for the floor to be Pareto improving is that it is high enough to be binding for all individuals. Even in that case, because the equilibrium interest rate adjusts with the level of the savings floor, some individuals may prefer to commit to a future time path of consumption by facing a high interest rate (and no floor) rather than a high floor. An essential insight for understanding this result is to note that even those with little self-control (in an absolute sense) will choose to save a lot when the interest rate is high enough.     

Socioeconomic Status and Obesity Gradient over Age: New Evidence from China

This paper presents a systematic analysis of the impact of socioeconomic status (SES) on overweight and obesity in China and investigates how and why the SES-obesity gradient differs with age. Using a longitudinal sample drawn from the China Health and Nutrition Survey (CHNS), I find that body mass index (BMI) is positively associated with SES during early childhood but becomes inversely related to childhood SES as children age into adulthood. Estimation results show that children from low SES families are less likely to be overweight or obese than their median and high SES peers. The results from subsamples stratified by living area reveal that the SES gaps of obesity are generally larger for urban residents than rural residents. Females are significantly less likely to be overweight than males in China. The SES during childhood has independent effects after controlling for respondents’ contemporaneous SES. The relationship between the contemporaneous SES of a male adult and his chance of being overweight or obese is significantly positive, while the contemporaneous SES of a female adult is negatively related to her chance of being overweight or obese.     

Hyperbolic discounting and the standard model: Eliciting discount functions

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.     

The effect of disability income on retirement decisions and wealth

Using the 2008 National Longitudinal Survey of Youth, this study examines the impact of receiving disability income on a respondent’s decision to calculate a retirement income need, use tax-advantaged accounts and accumulate retirement wealth. Respondents who received disability income were 4.4% less likely to report calculating a retirement income need and 4.5% less likely to report using a tax-advantaged account, compared to a reference group of respondents who did not receive disability income. Respondents who received disability income also accumulated 41% less retirement wealth compared to the same reference group.     

Empirical and public choice evidence for hyperbolic social discount rates and the implications for intergenerational discounting

The derivation of the correct discount rate for intergenerational projects in Cost Benefit Analysis is particularly contentious. Public choice has resulted in lower discretionary exponential discount rates for many intergenerational projects in Britain and the USA. This is shown to be strong indirect evidence that the true social discount rate may be a hyperbolic (rather than an exponential) function. There is also empirical evidence for this hypothesis. The hyperbolic nature of discounting is also a standard finding in the behavioural sciences. For intergenerational time frames hyperbolic discount rates should be employed together with exponential discount rates in cost-benefit sensitivity analyses.Sincere thanks to Maureen Cropper and Paul Portney for supplying their survey results and to Elaine Barrow and Phillip Judge for graphics assistance. Two anonymous referees also provided valuable comments.     

Hyperbolic discounting and the time-consistent solution of three canonical environmental problems

In this paper I propose a time-consistent method of discounting hyperbolically and apply it to three canonical environmental problems: (i) optimal renewable resource use, (ii) the tragedy of the commons, and (iii) economic growth and pollution. I show that, irrespective of potentially high initial discount rates, time-consistent hyperbolic discounting leads always to a steady state of maximum yield, or, if the environment enters the utility function, a steady state where the Green Golden Rule applies. While (asymptotic) extinction is a real threat under exponential discounting it is impossible under time-consistent hyperbolic discounting. This result is also confirmed for open-access resources. In a model of economic growth and pollution, hyperbolic discounting establishes the Golden Rule of capital accumulation and the modified Green Golden Rule.     

Saving and retirement behavior under quasi-hyperbolic discounting

This paper investigates saving and retirement behavior using a quasi-hyperbolic discounting model with endogenous labor supply. The behavior of quasi-hyperbolic-discounting consumers is compared with optimal behavior, which is obtained under exponential discounting. The quasi-hyperbolic discounters, whether naïve or sophisticated, under-save and retire early compared with an exponential discounter, if and only if the present-biased marginal utility of future consumption decreases with stronger present bias. Logarithmic utility functions and constant-absolute-risk-aversion utility functions can both exhibit this property. In other words, quasi-hyperbolic discounting explains why, consistent with previous empirical studies, under-savers might also be early retirers. Under logarithmic utility, a wage tax and an interest subsidy can counteract the under-saving and early retirement and improve consumer welfare.     

DEMAND RESPONSE TO COST SHARING UNDER MANAGED HEALTH CARE

We use 1996 Medical Expenditure Panel Survey to examine the demand response of ambulatory medical services to demand-side cost sharing under managed health care and find that demand response to a coinsurance rate is less than that under conventional plans. To address the selection problem, only respondents who were offered a single insurance plan from private establishments are studied. Our results show that managed care, relying on different approaches to ration, has blunted demand response. This suggests that in a managed care context, increasing demand-side cost sharing will reduce costs to plans mainly by shifting costs to enrollees. ( JEL I11)     

Understanding intertemporal choices

Previous experimental results show clearly that many subjects do not optimize when solving a life-cycle consumption problem. What do they do? This paper attempts to resolve this question, looking at the discounting, hyperbolic and rolling models as possible explanations. Data from two experiments (one an experiment with a typical subject pool and the second an experiment with subjects from the CentER panel) is used, and the advantage of having experimental data is exploited, which means that one can actually estimate the hyperbolic model. It is shown that the (exponential) discounting model appears to give the best explanation – suggesting that subjects do look ahead (as they should) but increasingly less as time passes (as they should not in the context of these experiments).     

Employed Job Search among Young Workers: Do Women Still Search Differently than Men in the Internet Age?

Using data from the 2008–2011 waves of the National Longitudinal Survey of Youth 1997, this study explores the job search methods and strategies utilized by young workers. Although women are found to be marginally less likely to engage in on-the-job search than men, when they do they are equally likely to use the internet. The most important gender difference identified is that marriage serves as a strong inhibiting factor to search, both online and offline, for women but not so for men. In terms of search methods, men and women show almost identical patterns of usage. While there is substitution between online and offline search within particular method categories, employed searchers are generally using the internet as a complement to rather than as a replacement for more traditional offline search methods.     

The transition from paid to self-employment in Canada: the importance of push factors

The share of self-employment in total employment has been growing in Canada throughout the 1990s. Recent research for Canada and elsewhere suggests that some workers may be ‘pushed’ into self-employment as a response to inadequate opportunities in the paid sector. Examining transitions from paid work to selfemployment using the Labour Market Activity Survey, this push hypothesis is tested using a number of indicators of the economic opportunities facing the newly selfemployed. It is found: (i) longer spells of joblessness favour self-employment, (ii) workers who collect unemployment benefits between jobs are less likely to become self-employed than are workers who did not, (iii) workers who left their previous, paid jobs involuntarily - i.e., due to layoff - were more likely to become selfemployed than those who left voluntarily, but less likely than workers who specified personal reasons for leaving, and (iv) self-employment decisions are independent of the health of the labour market as measured by the unemployment rate. These results are generally consistent with the push hypothesis but provide more ambiguous evidence than found in some other studies.     

The Sins of the Fathers: Intergenerational Income Mobility in China

This paper aims to obtain an accurate estimate of China's intergenerational income mobility and to present evidence on its distributional pattern. Using panel data from the China Health and Nutrition Survey (CHNS) over the period 1989–2009, I find that China is less mobile than most developed countries. Then, I employ five different approaches to investigate the distributional pattern of China's intergenerational mobility across income levels. The results suggest that poor families have relatively high mobility, indicating opportunities for the poor children to escape poverty. Finally, I show that while wealthy fathers are likely to pass on their favorable economic status to their sons, rich sons come from a very wide range of family economic backgrounds.     

Wages in a growing Russia

The robust Russian economic recovery after the 1998 financial crisis raised the economic standing of the population, especially for lowly paid workers, most of whom are women. In this paper I use the Russian Longitudinal Monitoring Survey from 1996 through 2002 to ask whether this helped to reduce the gender wage gap. I first focus on those whose wages are paid in full. Next, I ask about the gender composition of wage arrears as the overall extent of wage arrears dropped from 60 to 20 per cent after the 1998 crisis. I show that a temporary widening of the overall gender wage gap in 2000 is due to low‐wage women becoming more likely to receive their wages in full than low‐wage men. Except for this effect, the male–female pay difference in Russia exhibits a stable pattern.     

Employer-supported training in Canada and its impact on mobility and wages

Using information on job histories and on two training questions contained in Statistics Canada's Follow-Up to the School Leavers Survey, this paper seeks to answer three basic questions: 1) what are the characteristics of the trainees?; 2) Does the receipt of employer-supported training cause an increase in the wage paid to those young workers?; and 3) Does it improve the degree of job attachment?; I find that more educated young people are somewhat more likely to be trained than high school dropouts although there is strong evidence of selectivity as employers clearly seem to support training for those that have the most “favorable” characteristics. Also, controlling for unobserved individual characteristics, I find that training has a sizeable wage impact for men while the effect is much more modest for women. Finally, results using Chamberlain (1985) fixed-effects hazard model show that the conditional probability of the employment relationship being terminated decreases substantially for trainees, which is consistent with the notion that the skills learned by trainees may have a sizeable firm-specific component. First version received: October 2000/Final version received: February 2002  I would like to thank Nathalie Viennot-Briot for excellent research assistance, as well as Claude Montmarquette and an anonymous referee for useful comments and suggestions. Financial support from Human Resources Development Canada is gratefully acknowledged.     

The gender gap in university enrolment: Do parents play a role beyond investing in skills?

Young men are far less likely than women to attend university across most OECD countries. I use data from the Youth in Transition Survey (YITS) to investigate this issue in the Canadian context, focusing on how parents might influence this gender gap. In particular, my goal is to isolate the incremental effect of parents’ valuations of education during the teenage years, holding constant the stock of skills acquired up to that point. To estimate this effect, I use a factor model based on a framework developed by Foley et al. (2014). My results confirm the importance of skills in determining the gender gap in university attendance. I also find that differences in the distribution of parental valuations of education account for 22% of the gender gap in the YITS data, pointing toward an important role that parents play, not accounted for in prior work.     

中国城乡老年人口状况追踪调查抽样与加权方法研究

对2000年12月、2006年6月和2010年12月开展的三次中国城乡老年人口状况追踪调查的抽样方法、数据评估和加权模型做了详尽介绍,以便为各界学者、研究人员和在读研究生使用这套数据时,对数据来源有充分了解。按与人口规模成正比的概率抽样(PPS)方法进行分级多阶段抽样框,对涉及的2万名老年人入户调查所获得的原始数据,利用调查时点左右的人口普查或1%人口抽样调查60周岁及以上人口相关结果,通过相应的加权评估,足以推论调查时点我国大陆地区老年人口的总体状况,亦可对五年内的变化状况做短期估值预测。