the impact of possible climate catastrophes on global warming policy abstract recent studies on global warming have introduced the inherent uncertainties associated with the costs and benefits of climate policies and have often shown that abatement policies are likely to be less aggressive or postponed in comparison to those resulting from traditional cost benefit analyses cba yet those studies have failed to include the possibility of sudden climate catastrophes the aim of this paper is to account simultaneously for possible continuous and discrete damages resulting from global warming and to analyse their implications on the optimal path of abatement policies our approach is related to the new literature on investment under uncertainty and relies on some recent developments of the real option in which we incorporated negative jumps climate catastrophes in the stochastic process corresponding to the net benefits associated with the abatement policies the impacts of continuous and discrete climatic risks can therefore be considered separately our numerical applications lead to two main conclusions i gradual continuous uncertainty in the global warming process is likely to delay the adoption of abatement policies as found in previous studies with respect to the standard cba however ii the possibility of climate catastrophes accelerates the implementation of these policies as their net discounted benefits increase significantly

possibility of dying as a unified explanation of why we discount the future get weaker with age and display risk aversion i formulate a simple and parsimonious evolutionary model that shows that because most species face a possibility of dying because of external factors called extrinsic mortality in the biology literature it can simultaneously explain a why we discount the future b get weaker with age and c display risk aversion the paper suggests that testable restrictions across species across time or across genders among time preference aging and risk aversion could be analyzed in a simple framework jel a10 d90

defining the value of a statistical life reply abstract in general empirical estimates of the value of a statistical life vsl are biased however as pointed out by blomqvist 2001 a true blip in the hazard rate can be used to obtain an exact estimate of the vsl the question remains whether individuals and markets are able to value such short drops in the hazard rate

measuring risk reduction benefits with discounted longevity there are many ways to assess the benefits and costs of risk reduction policies this paper shows that discounted longevity as a measure of benefits and the negative of net output as a measure of costs can be deduced from the shepard and zeckhauser utility maximization model

rates of time preference and valuations of the duration of life abstract this paper develops a multi period markov model of the lifetime choice of occupational fatality risks the empirical model analyzes the wage effects of job risks using the 1982 university of michigan panel study of income dynamics in conjunction with death statistics from the u s national traumatic occupational fatality survey evidence regarding workers intertemporal choices with respect to risks with long term implications is broadly consistent with rational behavior workers implicit real rate of time preference with respect to future life years equals approximately 11 percent this rate of time preference decreases with education

future costs in economic evaluation a comment on lee in a recent article in this journal lee argued that indirect medical costs should be ignored in economic evaluations to reach this conclusion lee uses an unrealistic and uncommon budget constraint this comment highlights a number of methodological problems in lee s analysis moreover it highlights that looking at current practice of economic evaluation lee s model implies the inclusion rather than the exclusion of indirect medical costs

public and private expenditures on health in a growth model abstract this paper introduces endogenous longevity into an otherwise standard overlapping generations model with capital in the model a young agent may increase the length of her old age by incurring investments in health such private health investments are assumed to be more productive if accompanied by complementary tax financed public health programs the presence of the public input in private longevity is shown to expose the economy to aggregate endogenous fluctuations and even chaos and such volatility is impossible in its absence the model is capable of generating dramatic reversals in life expectancy as has been observed in many countries

optimal retirement with increasing longevity we develop an optimizing life cycle model of retirement with perfect capital markets we show that longer healthy life expectancy usually leads to later retirement but with an elasticity less than unity we calibrate our model using data from the us and find that over the last century the effect of rising incomes which promote early retirement has dominated the effect of rising lifespans our model predicts continuing declines in the optimal retirement age despite rising life expectancy provided the rate of real wage growth remains as high as in the last century

an empirical model of labor supply in a life cycle setting this paper formulates and estimates a structural intertemporal model of labor supply using theoretical characterizations derived from an economic model of lifetime behavior a two step empirical analysis yields estimates of intertemporal and uncompensated substitution effects which provide the information needed to predict the response of hours of work to life cycle wage growth and shifts in the lifetime wage path

recognizing progeny in the value of life abstract this note generalizes the value of life to incorporate the preferences for descendants of a dynastically altruistic decision maker it derives the value of progeny and shows how it depends on the benthamite vs millian nature of dynastic altruism

willingness to pay for car safety evidence from sweden this study estimates a marginal willingness to pay wtp function for a road mortality risk reduction observed marginal wtp from the swedish car market is used and found to be positively correlated with the baseline risk of the cars no statistically significant relationships between examined owner attributes e g wealth and background risk and marginal wtp are found when comparing the estimated monetary value of a non marginal risk reduction derived from the integral of the marginal wtp function with an estimate based on marginal wtp we find in line with expectations that the difference between the estimates is negligible for smaller risk reductions and small 4 10 also for relatively large risk reductions

optimal timing problems in environmental economics abstract because of the uncertainties and irreversibilities that are often inherent in environmental degradation its prevention and its economic consequences environmental policy design can involve important problems of timing i use a simple two period model to illustrate these optimal timing problems and their implications for environmental policy i then lay out and solve a continuous time model of policy adoption in which the policy itself entails sunk costs and environmental damage is irreversible the model generalizes earlier work in that it includes two stochastic state variables one captures uncertainty over environmental change and the other captures uncertainty over the social costs of environmental damage solutions of the model are used to show the implications of these two types of uncertainty for the timing of policy adoption

the effect of increased longevity on capital accumulation one of the more startling demographic trends of the 1970 s has been the sharp rise in lifespan in the united states between 1970 and 1980 the life expectancy of 25year old men and women increased by at least two years while longevity has been steadily rising for many decades the recent spurt has hastened the trend the increase for both men and women in the 1970 s more than doubled the improvement of the 1960 s 1 the 1970 s were also characterized by a decline in labor force participation of older workers although rising income and increased disability payments may have explained some of the decline donald parsons 1980 it seems clear that expanding longevity has not been strongly associated with deferred retirement daniel hamermesh 1984 2 thus the retirement years have assumed greater importance in financial planning for the consumer as he or she retires earlier and lives longer the traditional life cycle model would predict greater savings rates as consumers increase accumulation of assets for their retirement consumption while young would drop and there might be an increase in labor supply as individuals substitute leisure while young for greater levels of life cycle consumption even under a social security system as long as the current generation s tax liabilities reflect their longer lifespan total savings private plus public should also rise 3 the predicted increase in savings is substantial a simple example using the modigliani ando brumberg life cycle model can illustrate the extent of the savings shift assume that earnings and consumption are constant over working years and lifespan respectively and that the interest rate is zero consumption is then a constant proportion k of earnings where k is the ratio of working years to one s lifespan if consumers made plans based on average lifespan the representative 25 year old would have saved 18 percent of earnings in 1970 1 40 49 when he plans to retire at age 65 and expects to live until age 74 in 1980 after a rise in life expectancy of two years the representative 25 year old would have increased savings to 21 percent of earnings or a net rise in the savings rate per worker of 17 percent that is this simple life cycle model implies that savings in the last decade should have risen other things held constant by approximately 17 percent or about 80 billion dollars per year the evidence from aggregate time series data appears to contradict the life cycle model s prediction of rising savings rates the net private savings rate in the united states declined from 7 8 percent of nnp in 1970 to 6 2 percent in 1980 while alan auerbach 1982 has suggested that some of the reported decline in savings may be caused by mismeasurement it seems clear that there has been no substantial rise in the savings rate there are numerous explanations for department of economics university of virginia charlottesville va 22901 i am grateful to maxim engers daniel hamermesh william r johnson laurence j kotlikoff john strauss and especially james davies and john r wolfe for helpful suggestions and comments life table data can be found in daniel hamermesh 1985 the life insurance fact book various years or in unpublished form from the national center for health statistics 2john wolfe 1983 provides an ingenious argument for why the social security benefit schedule has induced those with shorter life expectancies to retire early we might therefore expect some rise in the average retirement age as those expecting to live longer defer retirement until age 65 3if the social security taxes do not rise as expected lifespan increases perhaps because current tax proceeds are paid out as current benefits rather than retained in a trust fund young workers will save more to offset the lower expected benefits in the future 4in a two period model the percentage change in savings by the young is equal to the percentage change in aggregate savings

life cycle responses to health insurance status this paper studies the lifetime effects of exogenous changes in health insurance coverage e g medicare ppaca termination of employer provided plans on the dynamic optimal allocation consumption leisure health expenditures status health and wealth and welfare we solve simulate and structurally estimate a parsimonious life cycle model with endogenous exposure to morbidity and mortality risks and exogenous health insurance by varying coverage we identify the marginal effects of insurance when young and or when old on allocations statuses and welfare our results highlight positive effects of insurance on health wealth and welfare as well as mid life substitution away from healthy leisure in favor of more health expenses caused by peaking wages and accelerating health issues

uncertain lifetimes retirement and economic welfare the effect of increased life expectancy on retirement age is ambiguous because a change in the survival probability is analogous to a change in intertemporal prices it is shown that the decision to retire earlier or later depends on the old age saving behavior early retirement could emerge if one saves in old age it is also shown that the effect of intertemporal substitutions arising from the imperfection of the annuity market could produce a tilt to the reservation wage profile which in turn makes early retirement possible copyright 1991 by the london school of economics and political science

expectations life expectancy and economic behavior this study analyzes responses to a questionnaire designed to elicit subjective expectations and probabilities of survival people do extrapolate past improvements in longevity when they determine their subjective horizons and they are fully aware of levels of and movements within todays life tables the subjective distribution has greater variance than its actuarial counterpart and the subjective variance decreases with age the implications of these findings for optimal social security for the construction of annuities for the analysis of savings behavior and for evaluating lifetime earnings are discussed the data were collected in the united states from a sample of 411 white male economists and a sample of 363 white males in a midwestern smsa excerpt

a theory of health investment under competing mortality risks in this paper we present a theory of health investment when there are multiple causes of death we analyze the optimal investment rules and the comparative statics in particular we examine the conditions under which a cause specific intervention has a spillover effect by spillover effect we mean a price reduction in one cause specific health investment would increase all other investments we also study the strength of the spillover effect which is measured in terms of cross price elasticities we find that while a cause specific intervention might not be wasteful the spillover effect would not be large either

a general model of r d competition and policy this article constructs a model of r d with heterogeneous firms each firm s probability of success is a function of its sunk and recurrent r d expenditures the social gains from an innovation are not fully captured by the successful firm the comparison of the social optimum and the market equilibrium involves balancing spillover and crowding effects pigovian corrective policies as well as strategic policies for a subset of colluding firms are discussed

intergenerational flows of time and goods consequences of slowing population growth it is feared that low fertility and older age distributions in the developed countries might cause lower life cycle consumption because of the increased pension and health cost burden the theoretical literature on intergenerational transfers has addressed this question but has considered only the consumption of market goods and has made no serious empirical attempt to measure the theoretical concepts necessary to assess the problem this paper develops a theoretical model of intergenerational transfers incorporating time use with the aid of time budget and consumer expenditure surveys empirical estimates of the age profiles of various types of time and goods consumption are presented and we conclude that 1 the net direction of intergenerational transfers is from younger to older ages 2 under the golden rule assumption these transfers largely constitute an externality to childbearing and 3 they are not large enough to offset the capital dilution effect that would result from higher fertility a

public goods and the value of product quality regulations the case of food safety abstract the paper examines preferences for product quality regulations our premise is that preferences for product quality regulations derive from preferences for both private and public goods the model is used to explain public attitudes toward a referendum measure to eliminate pesticide residues on food results from a survey of consumers are consistent with the conceptual model and show that preferences for public goods influence support for the product quality regulation the results help explain why consumption behavior is a poor predictor of political behavior and have implications for methods that use voting and market behavior to value public goods

strategic growth options we provide a strategic rationale for growth options under uncertainty and imperfect competition in a market with strategic competition investment confers a greater capability to take advantage of future growth opportunities this strategic advantage leads to the capture of a greater share of the market either by dissuading entry or by inducing competitors to make room for the stronger competitor as a result of this strategic effect payoffs are in a rough sense more convex than in the case of no investment in a growth option when the strategic advantage is strong increased uncertainty encourages investment in growth options higher uncertainty means more opportunity rather than simply larger risk if the strategic effect is weak the reverse is true on the other hand an increase in systematic risk discourages the acquisition of growth options our results contradict the view that volatility is a strong disincentive for investment

comorbidities and the willingness to pay for health improvements we show that the willingness to pay for health improvements increases with the severity and probability of occurrence of comorbidities this result which is obtained under mild restrictions on the shape of the utility function has important implications for cost benefit studies applied to health care in particular it implies that the discrimination of the elderly believed to be implicit in cost benefit analysis is less of a problem than commonly thought

the insurance value of medical innovation abstract economists think of medical innovation as a valuable but risky good producing health benefits but increasing financial risk for consumers and healthcare payers this perspective overlooks how innovation can lower physical risks borne by healthy patients facing the prospect of future disease we present an alternative framework that accounts for all these sources of value and links them to the value of healthcare insurance we show that any innovation worth buying reduces overall risk and generates positive insurance value on its own we conduct a stylized numerical exercise to assess the potential empirical significance of our insights our calculations suggest that conventional methods meaningfully understate the value of historical health gains and disproportionately undervalue treatments for the most severe illnesses where physical risk to consumers is the costliest these calculations also suggest that the value of physical insurance from new technologies may exceed the financial spending risk that they pose

optimal choice of health and retirement in a life cycle model abstract we examine within a life cycle model the simultaneous choice of health care and retirement together with consumption health tends to have an impact on retirement through morbidity determining earnings and the disutility of work and through longevity determining the need to accumulate retirement wealth conversely the age of retirement drives the demand for health care through the value of survival and the value of morbidity reductions we characterise the optimal relationship between health expenditure and retirement and apply our model to analyse the effects of moral hazard in the annuity market while moral hazard always induces excessive health investments and an excessive duration of working life it also triggers an excessive level of consumption if the impact of health on the disutility of work is sufficiently large we examine a transfer scheme and mandatory retirement as policies towards curtailing moral hazard numerical analysis illustrates the role of moral hazard in shaping the life cycle allocation

the wealth age relation among the aged aged people face the problem of allocating over the rest of their lifetimes the wealth that they have accumulated during their working years this problem is fairly complex because they are uncertain about the dates of their death and because they may wish to use their wealth to finance general consumption or hold it to meet emergencies leave estates or maintain power or status whether skilled at dynamic programming or not aged people effectively do make these decisions what are the results some studies of the entire lifetime pattern of saving and wealth tend to support the simple life cycle model in which the aged use up their wealth to help finance consumption harold lydall for example found saving rates to increase and then decrease with age in the whole population and to be negative for the group aged 65 and over guarded support for the theory was found by franco modigliani and albert ando in britain and by dorothy projector in the united states more recently a f shorrocks examined the lifetime pattern of wealth holding in estate tax data for a single cohort and found the hump pattern that is characteristic of life cycle saving other evidence on wealth holding runs contrary to this however in a study of estate tax returns in washington d c james d smith found that wealth increased with age among the aged after controlling for other demographic variables examining national estate tax data john brittain found wealth to increase with age in the united states and a b atkinson and a j harrison reported the same pattern in england and wales in a sample of tiaa annuity recipients analyzed by james mulanaphy over half reported that their total savings had increased during retirement and another quarter reported that their savings had remained about the same in this paper i examine wealth holding patterns among aged married couples using survey data representing the entire aged population of the united states in 1968 the statistical analysis serves as a test of the hypothesis that emerges from life cycle theory and provides some further exploration into the economic behavior of the aged i find that the aged tend to increase their wealth over time

your money or your life green growth policies and welfare in 2050 this paper proposes a simple index of economic progress that weighs in the monetary cost induced by climate change mitigation policies as well as the health benefits arising from the reduction in local air pollution the shadow price of pollution is calculated indirectly through its impact on life expectancy taking into account the health benefits of mitigation policies significantly reduces their monetary cost in china and india as well as in countries with large fossil based energy producing sectors australia canada and the united states

valuing future risks to life environmental policies that alter future mortality rates may affect both current and future generations this paper examines willingness to pay for future risk reductions from the perspective of the current generation the life cycle consumption saving model implies that an individual discounts future risks to himself at the consumption rate of interest if capital markets are perfect the consumption rate equals the market rate of interest otherwise the consumption rate exceeds the market rate and numerical results suggest that the implied discount factor may be substantial the overlapping generations model implies that a member of the current generation discounts the value of risks to future generations at the rate at which current consumption is substituted for a bequest

do the near elderly value mortality risks differently wage hedonic models are estimated with the health and retirement study to measure the risk wage tradeoffs value of statistical lives for older workers the analysis explicitly allows for multiple employment states including retirement using a multinomial selection model the results suggest that the oldest and most risk averse workers require significantly higher not lower compensation to accept increases in job related fatality risks

uncertain lifetime life protection and the value of life saving abstract the analytic innovation is treating life s end as uncertain and life expectancy as partly the product of individuals efforts to self protect against mortality and morbidity risks the demand for self protection is modeled in a stochastic life cycle framework under alternative insurance options the model helps explain the trend and systematic diversity in life expectancies across different population groups as well as the wide variability in reported value of life saving estimates the analysis yields a closed form solution for individuals value of life saving that is estimable empirically it reflects the impacts of specific personal characteristics and alternative insurance options on both life expectancy and its valuation

the economics of risks to life this study asks two questions 1 what is the net value to the representative individual over his life time of activities that alter age specific mortality risks 2 what is the cost to the representative individual of activities that take a life at random at a given age results derived from an economic demographic model with full age specific accounting have a strong actuarial flavor alterations in the mortality schedule caused say by a medical breakthrough should be assessed on the utility of expected additional life years production and reproduction less expected social costs of support loss of life at a specific age due to an accident say should be assessed on the opportunity costs of expected lost years of living lost production and reproduction less expected social support costs the results show that current methods in general leave out an important social transfer term that value of a life lost is highly age dependent and that the degree of diminishing returns to consumption is crucial in calculations of the economic cost of risks

effects of physical distancing to control covid 19 on public health the economy and the environment physical distancing measures are important tools to control disease spread especially in the absence of treatments and vaccines while distancing measures can safeguard public health they also can profoundly impact the economy and may have important indirect effects on the environment the extent to which physical distancing measures should be applied therefore depends on the trade offs between their health benefits and their economic costs we develop an epidemiological economic model to examine the optimal duration and intensity of physical distancing measures aimed to control the spread of covid 19 in an application to the united states our model considers the trade off between the lives saved by physical distancing both directly from stemming the spread of the virus and indirectly from reductions in air pollution during the period of physical distancing and the short and long run economic costs that ensue from such measures we examine the effect of air pollution co benefits on the optimal physical distancing policy and conduct sensitivity analyses to gauge the influence of several key parameters and uncertain model assumptions using recent estimates of the association between airborne particulate matter and the virulence of covid 19 we find that accounting for air pollution co benefits can significantly increase the intensity and duration of the optimal physical distancing policy to conclude we broaden our discussion to consider the possibility of durable changes in peoples behavior that could alter local markets the global economy and our relationship to nature for years to come

positive externalities of domestic biogas initiatives implications for financing domestic biogas programs are often justified on the basis of the private benefits and costs accruing to the individual households in terms of providing a superior cooking fuel improved indoor air quality and saving of time spent on collecting firewood this paper contends however that the economic surpluses from domestic biogas programs are realized beyond such narrowly defined project boundaries the paper maintains that economic value addition from the consumptive use of the biogas for cooking and the non consumptive and indirect value derived from the biogas plant providing feedstock for other processes and other such benefits as greenhouse gas mitigation positive externalities need to be accounted for the process approach adopted by this paper would enable an integrated view of the value chain and consequently a mechanism to reallocate costs and to distribute such surpluses

on the costs of food price fluctuations in low income countries abstract conventional welfare measures of the costs of food price fluctuations in low income countries are extended to allow for both economic growth and food security effects the analysis reveals that growth and food security effects may dominate more conventional welfare costs of food price fluctuations although estimating the empirical magnitude of the effects is hampered by the lack of consensus on the extent to which food price fluctuations actually reduce economic growth and food security even if the welfare costs of food price fluctuations are high there are many challenges to the design and successful implementation of price stabilization schemes

real options and preemption under incomplete information abstract this paper introduces incomplete information and preemption into an equilibrium model of firms facing real investment decisions the optimal investment strategy may lie anywhere between the zero npv trigger level and the optimal strategy of a monopolist depending on the distribution of competitors costs and the implied fear of preemption our model implies that the equity returns of firms which hold real options and are subject to preemption will contain jumps and positive skewness

compensating wage differentials and the value of life abstract this paper examines the relationship between willingness to pay and compensating wage differential measures of the value of a statistical life it resolves some recently noted discrepancies between such measures

on consumer preferences and the willingness to pay for term life insurance abstract we run a choice based conjoint cbc analysis for term life insurance on a sample of 2017 german consumers using data from web based experiments individual level part worth profiles are estimated by means of a hierarchical bayes model drawing on the elicited preference structures we then compute relative attribute importances and different willingness to pay measures in addition we present comprehensive simulation results for a realistic competitive setting that allows us to assess product switching as well as market expansion effects on average brand critical illness cover and underwriting procedure turn out to be the most important nonprice product attributes hence if a policy comprises their favored specifications customers accept substantial markups in the monthly premium furthermore preferences vary considerably across the sample while some individuals are prepared to pay relatively high monthly premiums a large fraction exhibits no willingness to pay for term life insurance at all presumably due to the absence of a need for mortality risk coverage we also illustrate that utility driven product optimization is well suited to gain market shares avoid competitive price pressure and access additional profit potential finally based on estimated demand sensitivities and a set of cost assumptions it is shown that insurers require an in depth understanding of preferences to identify the profit maximizing price

growth and welfare under endogenous lifetime we study the role of endogenous healthcare choices by households to extend their expected lifetimes on economic growth and welfare in a decentralized overlapping generations economy with the realistic feature that households savings are held in annuities we characterize healthcare spending in the decentralized market equilibrium and its effects on economic growth we then identify the moral hazard effect in healthcare investments when annuity rates are conditioned on average mortality and explain the conditions under which it will lead to over investment in healthcare moreover we specify the general equilibrium effects and macroeconomic repercussions associated with this moral hazard effect calibrating our model to oecd data we find that the moral hazard effect may be substantial and implies sizeable welfare losses of approximately 1 5 at a more general level our study suggests that welfare improvements from longevity increases may be quite lower than sometimes assumed when considered in planner economies

retirement pensions and ageing we study the effects of demographic shocks and changes in the pension system on the macroeconomic performance of an advanced small open economy facing a given world interest rate we construct an overlapping generations model which includes a realistic description of the mortality process individual agents choose their optimal retirement age taking into account the time and age profiles of wages taxes and the public pension system the early retirement provision in most pension systems acts as a trap inducing most workers to retire well before the normal retirement age simulations show that pension reform must be drastic for it to have any effects on the retirement behaviour of workers

health and other asset holdings despite clear evidence of correlations between financial and medical statuses and decisions most models treat financial and health related choices separately this article bridges this gap by proposing a tractable dynamic framework for the joint determination of optimal consumption portfolio holdings health investment and health insurance we solve for the optimal rules in closed form and capitalize on this tractability to gain a better understanding of the conditions under which separation between financial and health related decisions is sensible and of the pathways through which wealth and health determine allocations welfare and other variables of interest such as expected longevity or the value of health furthermore we show that the model is consistent with the observed patterns of individual allocations and provide realistic estimates of the parameters that confirm the relevance of all the main characteristics of the model

altruism fertility and the value of children health policy evaluation and intergenerational welfare abstract this paper accounts for the value of children and future generations in the evaluation of health policies this is achieved through the incorporation of altruism and fertility in a value of life type of framework we are able to express adults willingness to pay for changes in child mortality and also to incorporate the welfare of future generations in the evaluation of current policies our model clarifies a series of puzzles from the literature on the value of life and on intergenerational welfare comparisons we show that by incorporating altruism and fertility into the analysis of the recent u s experience the estimated welfare gain of a young adult from reductions in mortality easily doubles

labor market estimates of the senior discount for the value of statistical life abstract this article develops the first measures of age industry job risks to examine the age variations in the value of statistical life because of the greater risk vulnerability of older workers they face flatter wage risk gradients than younger workers which we show to be the case empirically accounting for this heterogeneity in hedonic market equilibria leads to estimates of the value of statistical life age relationship that follows an inverted u shape the estimates of the value of statistical life range from 6 4 million for younger workers to a peak of 9 0 million for those aged 35 44 and then a decline to 3 8 million for those aged 55 62 the decline of the estimated value of statistical life with age is consistent with there being some senior discount in the clear skies initiative analysis

health care expenditure in the last months of life in oecd countries a considerable share of health care expenditure hce is spent for the care of the terminally ill this paper derives the demand for hce in the last 2 years of life from a model that accounts for age mortality risk and wealth the empirical tests are based on data of deceased members of a major swiss sick fund the empirical evidence confirms most of the hypotheses derived from the model i e i hce increases with closeness to death ii for retired individuals hce decreases with age and iii low income individuals as compared to high income individuals incur lower hce in the last months of life

induced effects and technological innovation with strategic environmental policy abstract this paper investigates an environmental policy designed to reduce the emission of pollutants under uncertainty where the agents problem is formulated as an optimal stopping problem we first analyze the single agent s case according to pindyck pindyck r s 2002 optimal timing problems in environmental economics journal of economic dynamics and control 26 1677 1697 we then extend the model to the case in which there are two competing agents therefore we consider the external economic effects that are peculiar to an agent s environmental policy decision finally we consider the effect of technological innovation the results of the analysis suggest that if there are two competing agents they implement environmental policy simultaneously furthermore the threshold for implementing environmental policy is higher when there are two agents and how long these two agents take to implement environmental policy depends on the magnitude of the external economic effect furthermore when we consider the effect of technological innovation we show that the incentive to be the leader occurs if an additional condition is satisfied

the value of life and the rise in health spending over the past half century americans spent a rising share of total economic resources on health and enjoyed substantially longer lives as a result debate on health policy often focuses on limiting the growth of health spending we investigate an issue central to this debate is the growth of health spending a rational response to changing economic conditions notably the growth of income per person we develop a model based on standard economic assumptions and argue that this is indeed the case standard preferences of the kind used widely in economics to study consumption asset pricing and labor supply imply that health spending is a superior good with an income elasticity well above one as people get richer and consumption rises the marginal utility of consumption falls rapidly spending on health to extend life allows individuals to purchase additional periods of utility the marginal utility of life extension does not decline as a result the optimal composition of total spending shifts toward health and the health share grows along with income in projections based on the quantitative analysis of our model the optimal health share of spending seems likely to exceed 30 percent by the middle of the century

substance abuse treatment and mortality abstract drug overdose deaths which have more than doubled over the past decade represent a growing public health concern though substance abuse treatment may be effective in reducing drug abuse evidence for a causal effect of treatment on drug related mortality is lacking i analyze the effect of substance abuse treatment on mortality by exploiting county level variation in treatment facilities driven by facility openings and closings the estimates indicate that a 10 increase in facilities lowers a county s drug induced mortality rate by 2 the estimated effects persist across individual and county characteristics and further indicate that spillovers of treatment reduce other related causes of death

pricing and r d when consumption affects longevity we analyze goods for which the amount of consumption determines the duration of consumption focusing on health related consumption that affects longevity the characteristics of the demand for such goods lead to unique predictions about private pricing and investment in r d as well as the fiscal effects of public subsidies and taxes in particular we argue that there is an r d feedback for such goods when the market size expands through longevity induced population growth we also argue that as developed countries devote large shares of public spending to old age programs that may themselves affect longevity e g medicare and social security the nonstandard effects that these programs introduce may become increasingly important

survival versus consumption we develop an indirect method to estimate utility and willingness to pay wtp for reductions in the risk of death at various ages using a life cycle model of consumption we assume that an individual sets his consumption level each year so as to maximize his expected lifetime utility alternative assumptions about opportunities for borrowing and annuities characterize two polar types of societies in our robinson crusoe case an individual must be entirely self sufficient and annuities are not available in our perfect markets case an individual can borrow against future earnings and purchase actuarially fair annuities we show that under these assumptions wtp is the sum of livelihood discounted expected future earnings and consumer surplus to illustrate our methods we derive wtp for an average financially independent american man under plausible assumptions the model is calibrated to 1978 earnings e g 18 000 per year for men aged 45 54 with at least some income in the robinson crusoe case wtp increases from 500 000 at age 20 to a peak of 1 250 000 at age 40 and declines to 630 000 at age 60 in the perfect markets case age variations are less pronounced wtp is 1 050 000 at age 20 peaks at 1 070 000 at age 25 and declines to 600 000 at age 60 these results suggest that individuals value risks to their lives at several times the pro rata share of their future earnings

positive time preference the case for positive time preference is absolutely compelling unless there is an infinite time horizon with the expectation of unending technological advance combined with what we call drastically diminishing marginal utility this finding holds both in the positive and normative senses a corollary is that savings are interest elastic

life cycle effects on consumption and retirement the effects on consumption and retirement of the length of the horizon are examined at any given age people will work more and consume less if they expect to live longer the terman sample of gifted individuals in 1972 and 1977 is used to relate work status to the length of the horizon as proxied by parents longevity the results suggest the expected positive effect on effort but its magnitude is quite small the panel from the retirement history survey is used and effects of the horizon on consumption and retirement jointly are estimated for 1973 and 1975 there is a small positive effect of a more distant horizon proxied by the number of living parents on work effort and a stronger but still fairly small negative effect on consumption goods and leisure are consumed jointly suggesting their complementarity in household production and spending propensities out of social security wealth are far below those out of pension wealth

precautionary saving and accidental bequests this paper presents a simple general equilibrium model of precautionary saving and accidental bequests this model is used to analyze the implications of individual lifetime uncertainty for aggregate consumption and capital accumulation a precautionary demand for saving arises because an individual consumer does not know in advance the date at which he will die and he wants to avoid low levels of consumption in the event that he lives longer than expected an implication of this precautionary saving is that when death does occur the consumer is generally holding some wealth which is then passed on to his heirs in the form of an accidental bequest even if all consumers have the same ex ante mortality probabilities there will be some intracohort variation in the date of death consequently there will be a nondegenerate distribution of bequests left by consumers in a cohort this nondegenerate distribution of bequests left by one generation induces variation in the distributions of wealth consumption and bequests of subsequent generations the importance of bequests in aggregate saving has been established by laurence kotlikoff and lawrence summers 1981 who reported that 80 percent of u s household wealth is inherited wealth one interpretation of this finding is that the simple life cycle model without bequest motives is an inadequate description of saving behavior in the united states but the model i present demonstrates that accidental bequests by selfish consumers can account for a potentially sizeable fraction of aggregate wealth although some part of bequests especially by the wealthy undoubtedly results from an explicit bequest motive accidental bequests also play a role in the intergenerational transfer of wealth as well as in the intragenerational variation in wealth in order to focus on the role of accidental bequests i purposely exclude a bequest motive from the specification of the utility function the effects of lifetime uncertainty on individual consumption behavior were first examined formally in a seminal paper by menachem yaari 1965 yaari s model provided the basic framework for virtually all subsequent work on uncertain lifetimes including well known papers by nils hakansson 1969 stanley fischer 1973 robert barro and james friedman 1977 david levhari and leonard mirman 1977 and kotlikoff and avia spivak 1981 however all of these papers focused on the consumption decision of an individual and ignored the effect of accidental bequests on the behavior of the recipients of these accidental bequests 2 as will be shown at various points in this paper changes in the economic environment can have effects on aggregate behavior which differ sharply from the effects on individual behavior because of the endogenous adjustment of bequests the effects of department of economics harvard university cambridge ma 02138 this paper is a revised version of bequests and social security with uncertain lifetimes nber working paper no 1372 june 1984 i thank olivier blanchard john burbidge christopher cavanagh robert clower stanley fischer benjamin friedman elhanan helpman mervyn king nobuhiro kiyotaki laurence kotlikoff robert mcdonald james pesando julio rotemberg lawrence summers lars svensson mark watson and jeffrey wolcowitz for valuable conversations and correspondence i also thank the participants in seminars at boston university columbia university cornell university federal reserve board harvard university university of iowa mit university of minnesota university of montreal national bureau of economic research north carolina state university the wharton school and yale university and two anonymous referees for their helpful comments i also thank the national science foundation for financial support 1 in the presence of perfect annuity and life insurance markets there may or may not be bequests depending on the presence or absence of a bequest motive but there would be no accidental bequests 2 kotlikoff and spivak focus on the role of the family in providing an incomplete annuities market but stop short of a full scale overlapping generations model in which the distribution of bequests is determined endogenously

willingness to pay and sensitivity to time framing a theoretical analysis and an application on car safety stated preference sp surveys attempt to obtain monetary values for non market goods that reflect individuals true preferences numerous empirical studies suggest that monetary values from sp studies are sensitive to survey design and so may not reflect respondents true preferences this study examines the effect of time framing on respondents willingness to pay wtp for car safety we explore how wtp per unit risk reduction depends on the time period over which respondents pay and face reduced risk in a theoretical model and by using data from a swedish contingent valuation survey our theoretical model predicts the effect to be nontrivial in many scenarios used in empirical applications in our empirical analysis we examine the sensitivity of wtp to an annual and a monthly scenario our theoretical model predicts the effect from the time framing to be negligible but the empirical estimates from the annual scenario are about 70 higher than estimates from the monthly scenario

reducing dependence on chemical fertilizers and its financial implications for farmers in india the fertilizer intensive technology so long promoted in agriculture produced a green revolution but has brought long term damages to soil quality the technology now appears unsustainable for future agricultural development in india both on account of its ecological implications and the burden on the budget there is now a need to revisit the traditional methods once used in agriculture and to look for a judicious blend of chemical fertilizer based technology with organic manure since manures are relatively less productive in the short run there is an alarm that a shift in technology away from the chemical fertilizer towards organic manure may mean a compromise in production or may hurt the incomes of farmers this paper emphasizes the environmental benefits of a possible shift in agricultural technology while keeping in view the importance of sustaining crop yield levels and protecting farmers incomes considering two major crops in india in specific states the paper finds that over time while fertilizer use intensified several times over the use of manure in agriculture either stagnated or declined the manure market remained localized limited and unorganized and its price was significantly higher than fertilizer in terms of nutrients in contrast to the organized and state supported fertilizer market the paper estimates quadratic yield functions based on cross section household level data and using the prices faced by farmers as reported by official survey finds that in majority of the cases there will not be any financial loss resulting from a small shift in technology towards organic manure such a shift can however be considered feasible if the losing households are compensated and if manure price is kept in control by promoting a more dynamic manure market d 2004 elsevier b v all rights reserved

simulating soil fertility and poverty dynamics in uganda a bio economic multi agent systems approach declining soil fertility and increasing rural poverty are major problems facing sub saharan agriculture bio economic modeling has been used to analyze the complex interaction between ecological sustainability and rural poverty as well as to explore policy options promoting sustainable development this paper shows that these models can be further advanced by adopting an agent based modeling approach this gives a more realistic representation of diversity in socioeconomic and biophysical terms allows local interaction between households and can yield an ex ante assessment of the distributional consequences of policy intervention this paper describes the modeling approach and illustrates it with an empirical application to two village communities in the lake victoria crescent of uganda it is shown how the model system can be calibrated with and validated against empirical data the model is used to analyze the potential effect of short term credit mineral fertilizer and improved maize seed on poverty and sustainability simulation results suggest substantial reductions in poverty although the incidence of poverty would remain high and these innovations alone would have little effect on the long term ecological sustainability of the system

the recursive core core allocations may be defined for infinite horizon capital accumulation models if agents cannot trust each other in the sense of gale then agents may renege on their commitments their decisions appear time inconsistent a core allocation is a recursive core allocation provided no coalition can improve upon its consumption stream at any time given its accumulation of assets up to that period we show for every allocation of consumption in the initial core one can find a distribution of capital stocks among the agents where no coalition of agents will break the initial core contract at any date it follows that if the proper distribution of the streams of capital is achieved then the allocation in the core is also in the recursive core the latter therefore forges a link between the distribution of wealth capital the problem of trust and time consistent intertemporal contracts

your money or your life a prescriptive model for health safety and consumption decisions in this paper we develop a conceptual framework and model for valuing risks to an individual s health and life and to support decision making about investments in health quality of life and safety our treatment of health risks in the model builds on the popular quality adjusted life year qaly framework that balances health quality and length of life issues we extend this framework to consider financial concerns as well as health quality and length of life our model considers uncertainty in income and health and incorporates the decision maker s ability to adjust consumption over time in response to changes in expectations about health and income we use this model to study the optimal tradeoffs between financial gains or losses and improvements or reductions in health or longevity and apply it in two example medical decision problems

the welfare value of fda s mercury in fish advisory a dynamic reanalysis assessing the welfare impact of consumer health advisories is a thorny task recently shimshack and ward 2010 studied how u s households responded to fda s 2001 mercury in fish advisory they found that the average at risk household reduced fish consumption by 21 resulting in a 17 reduction in mercury exposure at the cost of a 21 reduction in cardioprotective omega 3 fatty acids based on a static assessment of the health costs and benefits shimshack and ward concluded that the advisory policy resulted in an overall consumer welfare loss in this note we propose a dynamic assessment that links the long term cardiovascular health effects of the advisory to life cycle consumption we find that under reasonable assumptions the welfare loss might be much larger than suggested our analysis highlights the importance of accounting for dynamic effects when evaluating persistent changes in exposure to environmental health risks

mortality transition and differential incentives for early retirement existing studies investigating the effect of mortality decline on retirement age usually specify the human mortality pattern in a parametric way and consider the derivative of optimal retirement age with respect to a change in the survival parameter however a survival parameter change affects the mortality rates at different ages simultaneously motivated by the stylized fact that mortality decline affects primarily younger people in the early phase of a mortality transition but mainly older people in the later phase we study the more fundamental question of how a mortality change at an arbitrary age affects optimal retirement age by using the volterra derivative for a functional we show that a mortality decline at an older age unambiguously leads to a later retirement age but a mortality decline at a younger age may lead to earlier retirement because of the substantial increase in the individual s expected lifetime human wealth

is there a meaningful definition of the value of a statistical life a definition of the value of a statistical life is derived this definition has a meaningful interpretation in terms of the monetary value of expected present value utility if consumption is age independent in all other cases empirical estimates of the value of a statistical life are biased estimators of the monetary counterpart to expected present value utility