a theory of socio economic disparities in health over the life cycle motivated by the observation that medical care explains only a relatively small part of the ses health gradient we present a life cycle model that incorporates several additional behaviours that potentially explain jointly a large part of observed disparities as a result the model provides not only a conceptual framework for the ses health gradient but more generally an improved framework for the production of health we derive novel predictions from the theory by performing comparative dynamic analyses more generally our comparative dynamic method can be applied to models of similar form e g human capital health deficits firm investment to name a few

comparative dynamics in a health investment model the method of comparative dynamics fully exploits the inter temporal structure of optimal control models i derive comparative dynamic results in a simplified demand for health model the effect of a change in the depreciation rate on the optimal paths for health capital and investment in health is studied by use of a phase diagram

risk sensitive dividend problems abstract we consider a discrete time version of the popular optimal dividend payout problem in risk theory the novel aspect of our approach is that we allow for a risk averse insurer i e instead of maximising the expected discounted dividends until ruin we maximise the expected utility of discounted dividends until ruin this task has been proposed as an open problem in gerber and shiu 2004 the model in a continuous time brownian motion setting with the exponential utility function has been analysed in grandits et al 2007 nevertheless a complete solution has not been provided in this work instead we solve the problem in discrete time setup for the exponential and the power utility functions and give the structure of optimal history dependent dividend policies we make use of certain ideas studied earlier in bauerle and rieder 2011 where markov decision processes with general utility functions were treated our analysis however includes new aspects since the reward functions in this case are not bounded

pioneering price level targeting the swedish experience 1931 1937 in september 1931 sweden became the first country to make the stabilization of the domestic price level the official goal of its monetary policy actually the only country that so far has adopted such an explicit price level target starting from the issues and concepts familiar from research and policy experience of inflation targeting as contrasted to price level targeting this paper examines the evolution of the swedish price level targeting in the 1930s we bring out a number of similarities and differences between price stabilization in the 1930s and in the 1990s

optimal aging and death understanding the preston curve does prosperity lead to greater longevity if so what is the strength of the income channel to address these questions we develop a life cycle model in which households are subject to physiological aging in modeling aging we draw on recent research in the elds of biology and medicine the speed of the aging process and thus the time of death are endogenously determined by optimal health investments a calibrated version of the model accounts well for the observed non linear cross country link between longevity and income also known as the preston curve

a new method of estimating risk aversion i show existing evidence on labor supply behavior places an upper bound on risk aversion in the expected utility model i derive a formula for the coefficient of relative risk aversion in terms of the ratio of the income elasticity of labor supply to wage elasticity and degree of complementarity between consumption and labor i bound the degree of complementarity using data on consumption choices when labor supply varies across states using labor supply elasticity estimates i find a mean estimate of 1 then show generating 2 requires that wage increases cause sharper labor supply reductions jel d81 j22

exchange rate policy and the zero bound on nominal interest rates in this paper we study the effectiveness of monetary policy in a severe recession and deflation when nominal interest rates are bounded at zero we compare two alternative proposals for ameliorating the effect of the zero bound an exchange rate peg and price level targeting we conduct this quantitative comparison in an empirical macroeconometric model of japan the united states and the euro area furthermore we use a stylized micro founded two country model to check our qualitative findings we find that both proposals succeed in generating inflationary expectations and work almost equally well under full credibility of monetary policy however price level targeting may be less effective under imperfect credibility because the announced price level target path is not directly observable

optimal interest rate rules and inflation stabilization versus price level stabilization abstract this paper compares the properties of interest rate rules such as simple taylor rules and rules that respond to price level fluctuations called wicksellian rules in a basic forward looking model by introducing appropriate history dependence in policy wicksellian rules perform better than optimal taylor rules in terms of welfare robustness to alternative shock processes and are less prone to equilibrium indeterminacy a simple wicksellian rule augmented with a high degree of interest rate inertia resembles a robustly optimal rule i e a monetary policy rule that implements the optimal plan and that is also completely robust to the specification of exogenous shock processes

price level targeting with evolving credibility abstract global learning dynamics for price level targeting plt monetary policy are analyzed and compared to inflation targeting in a nonlinear new keynesian model domain of attraction of target steady state is a new robustness criterion for policy regimes robustness of plt depends on whether a known target path is incorporated into learning credibility is measured by accuracy of this forecasting method relative to simple statistical forecasts evolving through reinforcement learning initial credibility and target price are key factors influencing performance model results are in line with the swedish experience of price stabilization in1930 s

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

negligible senescence an economic life cycle model for the future abstract we propose a model of aging and health deficit accumulation model with an infinite time horizon and a steady state of constant health the time of death is uncertain and endogenous to lifestyle and health behavior this setup can be conceptualized as a strive for immortality that is never reached we discuss adjustment dynamics and show that the new setup is particularly useful to understand aging of the oldest old i e of individuals for which morbidity and mortality have reached a plateau we then show how the existence of a steady state can be used to perform comparative dynamics exercises analytically as an illustration we investigate the effects of more expensive health investment and of advances in medical technology on optimal short run and long run health behavior

price scarcity rent and a modified r per cent rule for non renewable resources since hotelling s seminal paper on the optimal depletion of exhaustible resources much has been published yet confusion remains about whether scarcity rent and price increase or decrease as a resource is depleted when costs tend to rise with depletion we show that hotelling s fundamental results of rising scarcity rent and price paths are sustained and that the path of scarcity rent converges on the r per cent rule provided the objective function is concave predictions of non monotonic or declining scarcity rent paths are due to implicit assumptions that lead to a non concave objective function we identify the sources of these non concavities jel classification q30 d90 c60 prix rente de rarete et une regle modifiee du r pourcent pour les ressources non renouvelables malgre la volumineuse litterature specialisee qui a fleuri depuis qu hotelling a ecrit son memoire fondateur sur l epuisement optimal des ressources renouvelables une grande confusion regne toujours quand il faut etablir si la rente de rarete et le prix augmentent ou chutent a proportion que la ressource s epuise quand les couts tendent a croitre avec l epuisement ce memoire montre que les resultats fondamentaux obtenus par hotelling quant aux sentiers de croissance de la rente de rarete et du prix tiennent toujours et que le sentier de croissance de la rente de rarete converge vers la regle du r pourcent pourvu que la fonction objective soit concave les predictions de sentiers de croissance non monotone ou de declin de la rente de rarete presentees dans la litterature specialisee sont attribuables a des postulats implicites qui engendrent une fonction objective non concave les auteurs identifient les sources de ces non concavites

measuring benefits from air pollution control where do we stand measuring the benefits from reduced morbidity this paper presents a simple model of preventive health care similar to that of grossman 1972 and uses the model to define what a person would pay for a change in air quality the model assumes that one can build up resistance to acute illnes by increasing his stock of health capital however health capital decays at a rate which depends on air pollution for acute illness willingness to pay as derived from the model is greater than the benefit estimate computed using the damage function approach to illustrate the size of this discrepancy estimates of willingness to pay are computed using data from the michigan panel study of income dynamics the case for government providing information about risks rests secure in the theory of public goods informational scale economies and problems of dissemination conceivably call for a principal agent relationship in which certain types of decisions are delegated to the agency however the setting of standards and prohibitions is too simplistic it seldom recognizes that personal action tends to interact with and partially offset them 8 references

a model of the demand for longevity and the value of life extension we specify a demand function for longevity or quantity of life along with corresponding demand functions for indicators of quality of life and a value of health and life extension function we show that the demand for health must be derived in conjunction with that for longevity and the related consumption plan and that all choices depend on initial individual endowments and terminal conditions our comparative dynamics predictions indicate that optimal health and longevity are increasing functions of endowed wealth rather than necessarily current income that improvements in opportunities to produce health can accentuate the differences between endowed health and attained longevity levels and that the value individuals ascribe to their health may be increasing over a good portion of their life cycle we use this model to analyze observed empirical variations in levels and trends of life expectancy and in exposure to health risks across different population groups

the meaning of death some simulations of a model of healthy and unhealthy consumption simulations of a model of healthy and unhealthy consumption are used to investigate the impact of various terminal conditions on life span pathways of health related consumption and health a model in which life span and the death stock of health are fixed is compared to versions in which i the death stock of health is freely chosen ii life span is freely chosen iii both the death stock of health and life span are freely chosen the choice of terminal conditions has a striking impact on optimal plans results are discussed with reference to the existing demand for health literature and illustrate the application of iterative processes to determine optimal life span the role played by the marginal value of health capital in determining optimal plans and the importance of checking the second order conditions for the optimal choice of life span

intertemporal substitution and λ constant comparative statics abstract this paper characterizes intertemporal substitution along intertemporal consumption profiles a precise definition of the intertemporal elasticity of substitution is presented and compared to intertemporal analogs of the hicks allen and direct elasticities of substitution and the marginal utility of wealth or constant own price elasticity of demand in a model with perfect foresight i establish that constant comparative statics accurately characterizes intertemporal substitution if and only if lifetime utility is intertemporally additive i also demonstrate the usefulness of constant comparative statics in characterizing intertemporal substitution in models without time separability or perfect foresight

imperfect credibility and robust monetary policy this paper studies the behavior of a central bank that seeks to conduct policy optimally while having imperfect credibility and harboring doubts about its model taking the smets wouters model as the central bank s approximating model the paper s main ndings are as follows first a central bank s credibility can have large consequences for how policy responds to shocks second central banks that have low credibility can bene t from a desire for robustness because this desire motivates the central bank to follow through on policy announcements that would otherwise not be time consistent third even relatively small departures from perfect credibility can produce important declines in policy performance finally as a technical contribution the paper develops a numerical procedure to solve the decision problem facing an imperfectly credible policymaker that seeks robustness

longevity and public old age pensions i introduction conventional economic analysis of intertemporal or intergenerational resource allocation takes longevity as exogenously determined by biological or technological factors within this framework the institution of a mandatory public old age pensions of a pay as you go type unambiguously reduces capital accumulation the intuition behind this result is that when the young expect an old age pension after retirement and at the same time pay an earmarked payroll tax that lowers disposable income the ability and the incentive to save are reduced such a result however ignores the possibility that an individual who has a survivorship contingent title to an old age pension might use resources to increase the likelihood of survival to acquire the promised pension the fact that over the past century both longevity and the size of old age pensions have risen suggests that a more complete model that incorporates longevity as a choice variable may be useful in understanding the simultaneous increase in longevity and old age pensions ehrlich and chuma 1990 consider the demand for longevity in a world where the certain length of life is a fixed function of health care expenditures thus making longevity endogenous in their model consumers choose the optimal depreciation rate for human capital by choosing the path of health care expenditures their work paves the way for consideration of the effect of longevity contingent property rights on behavior in a more recent paper philipson and becker 1998 build on the work of ehrlich and chuma by modeling longevity contingent claims in the form of old age pensions among other things they find that an increase in a longevity contingent old age pension will induce individuals to live longer as a result of this longer life philipson and becker question the traditional result that pay as you go old age pensions always reduce the capital stock because workers who choose greater longevity may also choose to save more during their working years to finance their longer retirement period in this paper we introduce endogenous and uncertain lifetime into a two period overlapping generations olg model we depart from the traditional diamond type olg model by measuring longevity as the probability of survival into the second period and by allowing individuals to affect their survival probability through spending on longevity extending activities within this framework we examine the effects of a pay as you go old age pension on longevity and capital accumulation under two polar assumptions concerning the existence and absence of a fair intragenerational annuity market in either case the longevity effect of an increase in the old age pension is neutral while the capital stock effect is strictly negative if the interest rate and population growth rate are equal e g if the economy is on a golden rule path surprisingly increasing the old age pension produces both a negative longevity and savings effect for the more relevant case where the interest rate is larger than the population growth rate that an increase in the old age pension produces a negative capital stock effect is anticipated but the neutral or negative effect on longevity is counterintuitive it is counterintuitive because the empirical evidence seems to show lockstep increases in both longevity and government provided retirement benefits in the form of pensions and heath care benefits furthermore longevity insurance conjures up the moral hazard problem where increased utilization is expected with government provision the funding pool expands with use the cost being borne by workers the fact that the workers bear the burden of increasing the old age pension helps explain the longevity results we obtain when the population grows at the same rate as the return on capital an increase in the pension is offset by a dollar for dollar reduction in private savings leaving second period consumption unchanged

disinflations in a model of imperfectly anchored expectations abstract we study disinflations under imperfect credibility of the central bank we propose a framework to model imperfectly credible announcements and use it to study the distribution of the output cost for a given disinflation imperfect credibility is modeled as the extent to which agents rely on adaptive learning to form expectations lower credibility increases the mean variance and skewness of the distribution of the sacrifice ratio when credibility is low disinflations become very costly for adverse realizations of the shocks but an opportunistic disinflation a disinflation implemented after a period of below trend inflation can significantly lower the sacrifice ratio with simulated data we reinterpret the reduced form evidence in sacrifice ratio regressions coefficient estimates from these regressions can be misleading for policymakers considering the cost of disinflation

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

learning about monetary policy rules abstract we study macroeconomic systems with forward looking private sector agents and a monetary authority that is trying to control the economy through the use of a linear policy feedback rule we use stability under recursive learning a la evans and honkapohja learning and expectations in macroeconomics princeton university press princeton new jersey 2001 as a criterion for evaluating monetary policy rules in this context we find that considering learning can alter the evaluation of alternative policy rules

liquidity traps and expectation dynamics fiscal stimulus or fiscal austerity we examine global dynamics under infinite horizon learning in new keynesian models where the interest rate rule is subject to the zero lower bound as in evans guse and honkapohja 2008 the intended steady state is locally but not globally stable unstable deflationary paths emerge after large pessimistic shocks to expectations for large expectation shocks that push interest rates to the zero bound a temporary fiscal stimulus or a policy of fiscal austerity appropriately tailored in magnitude and duration will insulate the economy from deflation traps however fiscal switching rules that automatically kick in without discretionary fine tuning can be equally effective

optimal dividend and capital injection problem in the dual model with proportional and fixed transaction costs in this paper we consider the dividend payments and capital injections control problem in a dual risk model such a model might be appropriate for a company that specializes in inventions and discoveries which pays costs continuously and has occasional profits the objective is to maximize the expected present value of the dividends minus the discounted costs of capital injections this paper can be considered as an extension of yao et al 2010 we include fixed transaction costs incurred by capital injections in this paper this leads to an impulse control problem using the techniques of quasi variational inequalities qvi this optimal control problem is solved numerical solutions are provided to illustrate the idea and methodologies and some interesting economic insights are included

risk premium shocks and the zero bound on nominal interest rates there appears to be a disconnect between the importance of the zero bound on nominal interest rates in the real world and predictions from quantitative dsge models recent economic events have reinforced the relevance of the zero bound for monetary policy whereas quantitative models suggest that the zero bound does not constrain optimal monetary policy

the problem of population and growth a review of the literature from malthus to contemporary models of endogenous population and endogenous growth abstract this paper deals with the evolution of the literature on the problem of population and growth from the classical period to the recent literature on endogenous growth and development the problem concerns two distinct issues 1 how to explain the observed covariation of the levels and rates of growth of per capita income and population size over time and space and 2 how to improve the human condition represented by these variables through an accommodating social policy the evolution of the literature we survey is reflected by the progressive treatment of key variables as endogenous rather than exogenous to the growth process it is also reflected by a shift from the historical concern about population explosion and its implications for growth to the more recent concern about the association between growth and population implosion in many developed countries

a qualitative characterization of the competitive nonrenewable resource extracting firm abstract using variational differential equations a systematic qualitative analysis is carried out for the competitive nonrenewable resource extracting firm the parameters of interest are the output price variable input price discount rate lease length initial resource stock and various tax rates the effects of changes in these parameters on the entire optimal time paths of the current shadow value of the stock the resource stock and the extraction rate are characterized in the perturbed phase plane

five facts about prices a reevaluation of menu cost models are price decreases 3 the frequency of price increases covaries strongly with inflation whereas the frequency of price decreases and the size of price increases and price decreases do not 4 the frequency of price change is highly seasonal it is highest in the first quarter and then declines 5 we find no evidence of upwardsloping hazard functions of price changes for individual products we show that the first second and third facts are consistent with a benchmark menu cost model whereas the fourth and fifth facts are not

prices are sticky after all abstract economists have interpreted the evidence that prices change every four months as implying that sticky prices cannot be important for monetary transmission theory implies that this interpretation is correct if most price changes are regular but not if a large fraction are temporary as in the data since regular prices are much stickier than temporary ones our models predict that the stickiness of the aggregate price level matches that in a standard calvo model or a standard menu cost model in which micro level prices change about once a year in this sense prices are sticky after all

comparative dynamic analysis of the full grossman model the paper applies the method of comparative dynamic analysis to the full grossman model for a particular class of solutions it derives the equations implicitly defining the complete trajectories of the endogenous variables relying on the concept of frisch decision functions the impact of any parametric change on an endogenous variable can be decomposed into a direct and an indirect effect the focus of the paper is on marginal changes in the rate of health capital depreciation it also analyses the impact of either initial financial wealth or the initial stock of health capital while the direction of most effects remains ambiguous in the full model the assumption of a zero consumption benefit of health is sufficient to obtain a definite for any direct or indirect effect

imperfect credibility and the zero lower bound as the nominal interest rate cannot fall below zero a central bank with imperfect credibility faces a significant challenge to stabilize the economy in a new keynesian model during a large recession we characterize the optimal monetary policy at the zero lower bound for the nominal interest rate if credibility is imperfect confronting monetary policy communication of the u s federal reserve and the swedish riksbank with such a framework the credibility of both institutions is shown to have been low in the aftermath of the 2008 economic crisis

the science of monetary policy an imperfect knowledge perspective this paper reevaluates the basic prescriptions of monetary policy design in the new keynesian paradigm through the lens of imperfect knowledge we show that while the basic logic of monetary policy design under rational expectations continues to obtain perfect knowledge and learning can limit the set of policies available to central banks rendering expectations management in general more difficult nonetheless the desirability of some form of price level targeting inducing inertia in interest rate policy paramount under rational expectations is robust to the assumption of imperfect knowledge

the perils of taylor rules abstract since john taylor s 1993 carnegie rochester conf ser publ policy39 195 214 seminal paper a large literature has argued that active interest rate feedback rules that is rules that respond to increases in inflation with a more than one for one increase in the nominal interest rate are stabilizing in this paper we argue that once the zero bound on nominal interest rates is taken into account active interest rate feedback rules can easily lead to unexpected consequences specifically we show that even if the steady state at which monetary policy is active is locally the unique equilibrium typically there exist an infinite number of equilibrium trajectories originating arbitrarily close to that steady state that converge to a liquidity trap that is a steady state in which the nominal interest rate is near zero and inflation is possibly negative journal of economic literature classification numbers e52 e31 e63

non monotonic health behaviours implications for individual health related behaviour in a demand for health framework a number of behaviours influence health in a non monotonic way physical activity and alcohol consumption for instance may be beneficial to one s health in moderate but detrimental in large quantities we develop a demand for health framework that incorporates the feature of a physiologically optimal level an individual may still choose a physiologically non optimal level because of the trade off in his or her preferences for health versus other utility affecting commodities however any deviation above or below the physiologically optimal level will be punished with respect to health distinguishing between two individual types we study a the qualitative properties of optimal time paths of health capital and health related behaviour b the perturbations of the optimal time paths that result from changes in exogenous parameters and c steady state properties predictions of the model and the implications for empirical analysis are discussed at length some comments on potential future extensions conclude the paper

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

monetary policy in a low inflation environment developing a state contingent price level target a number of academic studies find that either price level targeting or temporary above average inflation are nearly optimal policies to address a liquidity trap crisis still central bankers and the public generally question whether even a temporarily higher inflation rate could be beneficial in addressing a liquidity trap or could be consistent with price stability over the longer term at the same time however the federal reserve s projections for high unemployment and low inflation do not seem to be consistent with the best monetary policies to address the fed s dual mandate responsibilities accordingly it is useful to seriously discuss these potentially beneficial alternative policies

consumption and investment demand when health evolves stochastically abstract the health capital model of grossman 1972 is extended to account for uncertainty in the rate at which a stock of health depreciates two general versions of the model are contemplated one with a fully functioning financial market and the other in its absence the comparative dynamics of the feedback form of the consumption and health investment demand functions are studied in these general settings where it is shown that the key to deriving refutable results is to determine how a parameter or state variable affects the expected lifetime marginal utilities of health and wealth to add further reach to the results a simplified stochastic control problem is explicitly solved yielding estimable structural feedback demand functions

quality of life and the wtp for an increased life expectancy at an advanced age abstract in this study we report an attempt to measure the value adult swedes impute to an increased survival probability at high ages a rating scale between the worst possible quality of life 1 and the best possible quality of life 10 is used to indicate the quality of life a person expects to achieve at an advanced age we find a highly significant correlation between this quality measure and the insurance premium a person is willing to pay in exchange for a programme increasing the expected length of life by one year conditional on having survived until the age of 75 years the maximum insurance premium the average person is willing to pay for such a programme is less than 1500 the willingness to pay increase with a person s age but at a low rate the implied average marginal rate of time preference is about 1 percent

health status and health dynamics in an empirical model of expected longevity expected longevity is an important factor influencing older individuals decisions such as consumption savings purchase of life insurance and annuities claiming of social security benefits and labor supply it has also been shown to be a good predictor of actual longevity which in turn is highly correlated with health status a relatively new literature on health investments under uncertainty which builds upon the seminal work by grossman grossman m 1972 on the concept of health capital and demand for health journal of political economy 80 223 255 has directly linked longevity with characteristics behaviors and decisions by utility maximizing agents our empirical model can be understood within that theoretical framework as estimating a production function of longevity using longitudinal data from the health and retirement study we directly incorporate health dynamics in explaining the variation in expected longevities and compare two alternative measures of health dynamics the self reported health change and the computed health change based on self reports of health status in 38 of the reports in our sample computed health changes are inconsistent with the direct report on health changes over time and another 15 of the sample can suffer from information losses if computed changes are used to assess changes in actual health these potentially serious problems raise doubts regarding the use and interpretation of the computed health changes and even the lagged measures of self reported health as controls for health dynamics in a variety of empirical settings our empirical results controlling for both subjective and objective measures of health status and unobserved heterogeneity in reporting suggest that self reported health changes are a preferred measure of health dynamics

grossman s missing health threshold we present a generalized solution to grossman s model of health capital 1972 relaxing the widely used assumption that individuals can adjust their health stock instantaneously to an optimal level without adjustment costs the grossman model then predicts the existence of a health threshold above which individuals do not demand medical care our generalized solution addresses a significant criticism the model s prediction that health and medical care are positively related is consistently rejected by the data we suggest structural and reduced form equations to test our generalized solution and contrast the predictions of the model with the empirical literature

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

the effect of the discount rate on depletion of exhaustible resources this paper argues that despite its widespread acceptance in the literature the basic proposition that a reduction an increase in the discount rate leads to greater conservation faster depletion of an exhaustible resource is not generally valid it shows that the effect of the discount rate on the rate of resource depletion depends on capital requirements for production of the substitute and extraction of the resource and on the size of the resource stock in fact it shows that there always exist at least two ranges of the resource stock size for which the effect is opposite to that conventionally believed

reference health and the demand for medical care we propose that health in prior periods termed reference health is theoretically and empirically relevant to the demand for medical care to address non normality in the distributions of medical care spending consumption and health we use a conditional density estimator nested in a finite mixture framework we find that reference health can help explain the variation in spending among individuals with the same contemporaneous health particularly in the top tail of the spending distribution we demonstrate that omitting reference health understates the potential cost savings of healthy aging initiatives by 50 percent this article is protected by copyright all rights reserved

alcoholism work and income this article reports on an empirical analysis of the relationships between alcoholism and income and working we show that the relationships between alcoholism and labor market success have important age or life cycle dimensions we present evidence that alcoholism may affect income more by restricting labor market participation than by affecting the wages of workers finally we demonstrate that the effects of alcoholism on earnings depend on the extent to which one controls for other covariates associated with alcoholism as such we suggest that there may be important indirect as well as direct effects of alcoholism on labor market success

evolution and human nature from an economic perspective on individual decision making human beings have three key characteristics preferences beliefs and rationality beliefs are the probabilities with which people think various outcomes will occur conditional on information that might be available preferences are the rankings over the set of gambles that are based on such beliefs over the outcomes rationality is the extent to which people succeed in choosing optimal actions in the light of their beliefs and preferences and the extent to which their beliefs are appropriately modified by their information economists typically impose only rather weak assumptions on preferences for example preferences are taken to be transitive and sometimes less explicitly exogenous and unchanging stronger assumptions are typically imposed on preferences in specific contexts however for example preferences over time might be represented by an additively separable function with constant rate of discount despite widespread recognition that this case is a special one further attitudes to risk are often represented by the expected utility theorem which rests on assumptions that are strong if also appealing the assumptions made on rationality in particular are usually very strong that is rationality in economic models usually entails the exact optimization of preferences and modification of beliefs in accordance with bayes theorem the economist s basic picture of preferences beliefs and rationality has been subject to challenges from a growing number of empirical anomalies the proposed explanations of these anomalies involve relaxing the assumptions that economists make on these preferences beliefs or rationality for example preferences

the taxation of nonreplenishable natural resources revisited abstract the theory of nonreplenishable resource extraction has been extended to allow for extraction costs which increase as deposits are increasingly depleted in these cases profit maximization may result in the cessation of extraction before reserves are totally exhausted the effect of various taxation policies on optimal extraction patterns in these models are derived with a few exceptions the results are that the imposition of a tax will cause operators to extract at faster rates over shorter periods of time and to reduce the total amount of ore extracted the analysis allows for an output price which increases over time

optimal social security in a dynastic model with human capital externalities fertility and endogenous growth abstract in this paper we investigate the optimal scale of pay as you go social security in a dynastic family model with human capital externalities fertility and endogenous growth human capital externalities reduce the return to human capital investment and hence lead to under investment in human capital and over reproduction of the population if the taste for the number of children is sufficiently weak relative to the taste for the welfare of children social security can be welfare enhancing by reducing fertility and raising human capital investment per child

portfolio selection in stochastic markets with hara utility functions in this paper we consider the optimal portfolio selection problem where the investor maximizes the expected utility of the terminal wealth the utility function belongs to the hara family which includes exponential logarithmic and power utility functions the main feature of the model is that returns of the risky assets and the utility function all depend on an external process that represents the stochastic market the states of the market describe the prevailing economic financial social political and other conditions that affect the deterministic and probabilistic parameters of the model we suppose that the random changes in the market states are depicted by a markov chain dynamic programming is used to obtain an explicit characterization of the optimal policy in particular it is shown that optimal portfolios satisfy the separation property and the composition of the risky portfolio does not depend on the wealth of the investor we also provide an explicit construction of the optimal wealth process and use it to determine various quantities of interest the return risk frontiers of the terminal wealth are shown to have linear forms special cases are discussed together with numerical illustrations

on adaptation and the demand for health the purpose of this paper is to analyse the impacts of adaptation to failing health this is done by integrating adaptation processes in a grossman type of pure consumption model model simulations show that adaptation affects the health variables by lowering the incentives to invest in health as well as smoothing the optimal health stock path over the life cycle whether or not the risk of mortality is an object of choice has important effects when studying adaptation as well as for the joint development of the health variables

demand for health a generalised grossman model the demand for health and medical care is analysed within a generalised grossman type health investment model its underlying assumptions are shown to differ from those employed earlier in a manner which avoids some of the criticisms levelled at grossman s model the comparative static predictions of the generalised model are examined and it is demonstrated that most previous health investment models are derivable from it also the present model is applicable to a new wider range of problems thus increasing the scope of economic explanations of health behaviour