quality competition with motivated providers and sluggish demand we study incentives for quality provision in markets where providers are motivated semi altruistic prices are regulated and firms are funded by a combination of block grants and unit prices competition is based on quality and demand adjusts sluggishly health or education are sectors in which the mentioned features are the rule we show that the presence of motivated providers makes dynamic competition tougher resulting in higher steady state levels of quality in the closed loop solution than in the benchmark open loop solution if the price is sufficiently high however this result is reversed if the price is sufficiently low and below unit costs sufficiently low prices also imply that a reduction in demand sluggishness will lead to lower steady state quality prices below unit costs will nevertheless be welfare optimal if the providers are sufficiently motivated

bequests gifts and social security this paper analyses the very long run or stationary state impact of an unfunded social security system we use an overlapping generations model framework a key feature is that while parents care about their children and can leave non negative bequests to them children also care about their parents and can make non negative gifts to them we show that the possibility of negative net bequests may make social security less harmful to private wealth accumulation than would otherwise be the case a subsidiary finding is that risk loving behaviour may emerge for some households due to the nature of intergenerational transfers within family lines

long term growth and short term economic instability when learning by doing is at the origin of growth the long run growth rate should be negatively related to the amplitude of the business cycle if human capital accumulation is increasing and concave in the cyclical component of production empirical evidence strongly supports this nding for industrialized countries and european regions using the standard control variables we nd that countries and regions that have a higher standard deviation of growth and of unemployment have lower growth rates the result does not come from an e ect of instability on investment the negative relation however does not hold for non industrialized countries for which learning by doing may not to be the main engine of growth 2000 elsevier science b v all rights reserved jel classixcation o40 e32

standard essential patents a major policy issue in standard setting is that patents that are ex ante not that important by being included into a standard may become standard essential patents in an attempt to curb the monopoly power that they create most standard setting organizations require the owners of patents covered by the standard to make a loose commitment to grant licenses on reasonable terms such commitments unsurprisingly are conducive to litigation this paper builds a framework for the analysis of these patents identifies several types of inefficiencies attached to the lack of price commitments and shows how structured price commitments restore competition and why such commitments may not arise spontaneously in the marketplace

price adjustment in the hospital sector we analyse the properties of optimal price adjustment to hospitals when no lump sum transfers are allowed and when prices differ to reflect observable exogenous differences in costs we find that a when the marginal benefit from treatment is decreasing and the cost function is the power function price adjustment for hospitals with higher costs is positive but partial if the marginal benefit is constant the price is identical across providers b if the cost function is exponential or it is separable in monetary and non monetary costs and linear in monetary costs price adjustment is positive even when the marginal benefit is constant c higher inequality aversion of the purchaser increases concentration in prices and lowers concentration in quantities d if some dimensions of costs are private information a higher correlation between the observable and unobservable cost component increases the optimal price for providers whose observable costs are above the average

hospital competition with soft budgets we study the incentives for hospitals to provide quality and expend cost reducing effort when their budgets are soft i e the payer may cover deficits or confiscate surpluses the basic set up is a hotelling model with two hospitals that differ in location and face demand uncertainty where the hospitals run deficits surpluses in the high low demand state softer budgets reduce cost efficiency while the effect on quality is ambiguous for given cost efficiency softer budgets increase quality since parts of the expenditures may be covered by the payer however softer budgets reduce cost reducing effort and the profit margin which in turn weakens quality incentives we also find that profit confiscation reduces quality and cost reducing effort first best is achieved by a strict no bailout and no profit confiscation policy when the regulated price is optimally set however for suboptimal prices a more lenient bailout policy can be welfare improving

the effects of hospitals governance on optimal contracts bargaining vs contracting we propose a two stage model to study the impact of different hospitals governance frameworks on the optimal contracts designed by third party payers when patients disease severity is the private information of the hospital in the second stage doctors and managers interact within either a bargaining or a contracting scenario in the contracting scenario managers offer a contract that determines the payment to doctors and doctors decide how many patients to treat in the bargaining scenario doctors and managers strategically negotiate on both the payment to doctors and the number of patients to treat we derive the equilibrium doctors payments and number of treated patients under both scenarios we then derive the optimal contract offered by the government to the hospital in the first stage results show that when the cost of capital is sufficiently low the informational rent is lower and the social welfare is higher in the contracting scenario

demographics productivity growth and the macroeconomic equilibrium i introduction the demographics in the united states are as in other industrial countries experiencing drastic changes the birth rate is falling while life expectancy is rising as a consequence the ratio of the elderly to the working age population is projected to rise sharply in the next fifty years the aging of the population imposes both real and imagined burdens on the economy aaron 1990 most importantly it is predicted to cause substantial increases in the tax rates needed to sustain existing social security benefits thereby bringing about an increase in conflict between the working and the elderly generations wildasin 1991 von weizsacker 1990 and verbon 1988 population aging also means it is more likely that the pay as you go system of financing social security will be dynamically inefficient hu 1993 in this case the economy is better served by switching to another financing system indeed a number of countries most notably chile have chosen to privatize their state pension systems more broadly there is evidence that the changing age distribution in the u s population has significantly affected consumption housing investment money demand and the labor force participation rate fair and dominguez 1991 and is potentially very important for explaining the u s rate of national saving for the next fifty years auerbach and kotlikoff 1990 it also affects capital accumulation by causing changes in family insurance and intergenerational trade ehrlich and lui 1991 existing studies of the economic effects of demographics assume either that both work hours and retirement behavior are exogenous or that work hours are endogenous but retirement behavior is exogenous for example cutler poterba sheiner and summers 1990 model the labor market effects of population aging by imposing the projected age distributions on the current labor force participation rates across age cohorts rather than on those corresponding to the projected demographics as such they implicitly assume exogenous work hours and concentrate on the age distribution effect of population aging auerbach and kotlikoff 1990 set an exogenous retirement age of sixty five although they allow endogenous determination of work hours feldstein 1980 provides evidence that incorporation of induced retirement improves the prediction of how social security affects capital accumulation likewise studies of the effects of demographic changes and their interactions with social security will be more fruitful if retirement decisions are explicitly recognized this is particularly true since the 1983 amendment to the social security act would gradually relax the retirement test thus removing the distortions that prevent retirement decisions from adjusting to changing demographics this paper provides a computational study of the effects of demographics on the macroeconomic equilibrium and welfare within the framework of an intertemporal optimizing model with age heterogeneity and endogenous productivity growth the model extends tobin 1967 and cass and yaari 1967 to allow for endogenous retirement decisions it differs from hu 1978 1993 in that it incorporates endogenous productivity growth a key feature that differentiates this analysis from previous studies is that retirement decisions are characterized by a binary choice of whether to work or not to work but work hours are exogenous during working years 1 to facilitate comparisons we also provide a simulation which shows what would happen if social security provisions were such as to prevent the retirement age from adjusting to the demographic changes to study the effects of demographics on the macroeconomic equilibrium involves explaining their effects on the labor force participation rate and aggregate consumption their interactions with social security and their implications for the welfare of the economy

the strategic bequest motive although recent research suggests that intergenerational transfers play an important role in aggregate capital accumulation our understanding of bequest motives remains incomplete we develop a simple model of strategic bequests in which a testator influences the decisions of his beneficiaries by holding wealth in bequeathable forms and by conditioning the division of bequests on the beneficiaries actions the model generates falsifiable empirical predictions that are inconsistent with other theories of intergenerational transfers we present econometric and other evidence that strongly suggests that bequests are often used as compensation for services rendered by beneficiaries

quality competition with profit constraints abstract firms in markets such as health care and education are often profit constrained due to regulation or their non profit status and they are often viewed as being altruistic towards consumers we use a spatial competition framework to study incentives for cost containment and quality provision by altruistic firms facing profit constraints if prices are regulated profit constraints lead to lower cost containment efforts but higher quality if and only if firms are sufficiently altruistic under price competition profit constraints reduce quality and cost containment efforts but lead to lower prices if and only if firms are sufficiently altruistic profit constrained firms cost containment efforts are below the first best while their quality might be too high or too low if prices are regulated profit constraints can improve welfare and be a complement or substitute to a higher regulated price depending on the degree of altruism

incentives for monitoring quality we analyze a procurement problem in which the quality of the delivered product can be observed perfectly by the buyer and supplier but may not be verifiable i e may not be observable to any third party we present a set of plausible conditions under which the equilibrium welfare of both the buyer and supplier is higher when quality is verifiable than when it is unverifiable the welfare gain for the privately informed supplier arises even when the buyer has all the bargaining power thus the interests of the buyer and supplier coincide with regard to whether delivered quality should be made verifiable

the effect of entry regulation in the health care sector the case of home health the consequences of government regulation in the post acute care sector are not well understood we examine the effect of entry regulation on quality of care in home health care by analyzing the universe of hospital discharges during 2006 for publicly insured beneficiaries about 4 5 million and subsequent home health admissions to determine whether there is a significant difference in home health utilization hospital readmission rates and health care expenditures in states with and without certificate of need laws con regulating entry we identify these effects by looking across regulated and nonregulated states within hospital referral regions which characterize well defined health care markets and frequently cross state boundaries we find that con states use home health less frequently but system wide rehospitalization rates overall medicare expenditures and home health practice patterns are similar removing con for home health would have negligible system wide effects on health care costs and quality

a model of longevity fertility and growth abstract economic and demographic outcomes are determined jointly in a dynamic general equilibrium model of longevity fertility and growth reproductive agents in overlapping generations mature safely through two periods of life and face an endogenous probability of surviving for a third period given this probability each agent maximises her expected lifetime utility by choosing consumption and the number of children child bearing is costly in the sense that time must be spent on child rearing activities rather than on production or education the model produces multiple development regimes which yield different predictions about life expectancy fertility timing of births and educational investment depending on initial conditions these predictions accord strongly with the empirical evidence on demography and development

a reexamination of the strategic bequest motive this paper investigates the strength of the empirical evidence of the strategic bequest hypothesis proposed by bernheim shleifer and summers 1985 at issue is whether bequests are primarily motivated by a desire to influnce the behavior of potential beneficiaries alternatively bequests may be motivated by altruism or risk aversion in the presence of incomplete annuity and health insurnace markets e g tomes 1981 hurd 1989

fertility choice land and the malthusian hypothesis in a standard overlapping generations growth model with a fixed amount of land and endogenous fertility the competitive economy converges to a steady state with a zero population growth rate and positive consumption per capita the malthusian hypothesis is interpreted as a positive statement about the relationship between population growth and consumption per capita when production exhibits diminishing returns to labor and there is a fixed amount of land essential for production even when individuals care only about the number of their children and not about their children s welfare the equilibrium is such that they eventually would choose to have only one child for each adult hence if malthus s positive check on population is the result of the response of optimizing agents to competitively determined prices malthus s pessimistic conjecture is not necessarily true even though his other assumptions hold from authors

business cycle models with endogenous technology this paper compares real and monetary business cycle models with and without endogenous technical change if technology is endogenous the properties of these models change significantly in particular both real and monetary models yield very similar output processes if growth is endogenous and changes in aggregate demand can result in permanent changes in productivity employment and output the effect of depreciation of technology is examined and the pattern of real wage movements over the cycle when money wages are fixed but technology is changing is briefly considered copyright 1990 by american economic association

economic growth with intergenerational altruism in this paper we study the properties of equilibria in an aggregative growth model with intergenerational altruism in this model each generation is active for a single period at the beginning of this period it receives an endowment of a single homogeneous good which is the output from a bequest investment made by the previous generation it divides the endowment between consumption and investment the return from this investment constitutes the endowment of the next generation each generation derives utility from its own consumption and that of its immediate successor however since altruism is limited in the sense that no generation cares about later successors the interests of distinct agents come into conflict models of this type have been used to analyze a number of issues concerning intergenerational altruism one line of research pursued by arrow 1973 and dasgupta 1974a elucidates the implications of rawls principle of just savings others beginning with phelps and pollak 1968 have addressed the question of how an altruistic growth economy might actually evolve over time topics of subsequent investigation have included the efficiency and optimality of equilibrium programs and the implications of intergenerational altruism for the distribution of wealth unfortunately the positive features of equilibrium programs have received little attention from previous authors aside from a few comments by kohlberg 1976 virtually nothing is known about the asymptotic behaviour of capital stocks in these models in particular will the long run capital stock which arises from intergenerational conflict be higher or lower than the turnpike associated with the solution to the optimal planning problem on a priori grounds the answer is not clear agents who take only a limited interest in the future will tend to bequeath less than those who are far sighted however since each generation views its children s bequest as pure waste it must bequeath a larger sum to obtain the same consumption value in this paper we obtain steady state results for equilibrium capital stocks completely analogous to the well known optimal planning results by comparing steady states we

dynamic efficiency in the gifts economy abstract in the standard analysis of overlapping generations economies with gifts from children to parents each generation takes the actions of other generations as given the resulting equilibrium is dynamically inefficient in reality however parents realize that children will respond to higher parental saving by reducing gifts for a broad class of gift economies this implicit tax on saving pushes the equilibrium to dynamic efficiency this result reestablishes the potential relevance of the gift model to the us economy renders moot an important part of the ricardian equivalence debate and provides a motivation for a type of social security system

optimal allocation of mri scan capacity among competitive medical departments we consider an mri scanning facility run by a radiology department with limited capacity several medical departments compete for capacity and have private information regarding their demand for scans the fairness of the capacity allocation by the radiology department depends on the quality of the information provided by the medical departments we employ a generic bayesian game approach that stimulates the disclosure of true demand truth telling so that capacity can be allocated fairly we derive conditions under which truth telling is a bayesian nash equilibrium the usefulness of the approach is illustrated with a case study

longevity and economic growth in a dynastic family model with an annuity market abstract this paper investigates the growth implication of rising longevity in a dynastic family model with an annuity market we show that rising longevity raises life cycle savings human capital investment labor supply and the growth rate of per capita income

mortality decline and long run economic growth this paper examines the impacts of mortality decline on long run growth in a dynastic family two sector growth model with social security a rise in longevity has direct effects on fertility human capital investment and growth as well as indirect effects through increasing unfunded social security contributions both the direct and indirect effects depend on the relative strength of the tastes for the number and welfare of children and may have different signs the net effects of rising longevity on fertility tend to be negative but positive on human capital investment and growth c 2001 elsevier science s a all rights reserved

contracting for health services when patient demand does not reflect quality this paper analyses contracts to keep down costs while maintaining quality of health services when patient demand does not reflect quality there is then a natural role for forms of contract that have emerged during the reforms of the nhs in britain that differ from pure fixed price or cost reimbursement contracts the optimal form depends on whether the provider is entirely self interested or benevolent in having genuine concern for patient welfare with fully benevolent providers there are roles for block and cost and volume contracts with partially benevolent providers some degree of cost sharing is typically optimal

self fulfilling mechanisms in bayesian games abstract amechanismfor a bayesian gamegis a mapping from the set of states of nature to the set of players actions isself fulfillingif players are truthful at the communication stage and given the information revealed by no player can gain in unilaterally deviating from the action prescribed by the mechanism we investigate the properties of self fulfilling mechanisms and we show in particular that they correspond to inert solutions of the infinitely repeated game generated byg we also discuss applications to market games regulation and r d games journal of economic literatureclassification numbers d82 c72

optimal dynamic volume based price regulation abstract we consider a model of optimal price regulation in markets where demand is sluggish and asymmetric providers compete on quality using a spatial model which is suitable to investigate the health care and education sector we analyse within a dynamic set up the scope for price premiums or penalties on volume under the assumption of symmetric cost information we show that the socially optimal time path of quality provision off the steady state can be replicated by a simple dynamic pricing rule where the dynamic part of the rule is ex ante non discriminatory in the sense that the price premium or penalty on volume is common across providers despite their differing production costs whether the price schedule involves a penalty or a premium on volume relates to two concerns regarding production costs and consumer benefits which go in opposite directions price adjustments over time occur only through the price penalty or premium not time directly which highlights the simplicity and thus applicability of this regulation scheme

hospital competition and quality with regulated prices we analyse the effect of competition on quality in hospital markets with regulated prices considering the effect of both introducing competition monopoly versus competition and increasing competition through either lower transportation costs increased substitutability or a higher number of hospitals with semi altruistic providers and a fairly general cost structure we show that the relationship between competition and quality is generally ambiguous in contrast to the received body of theoretical literature this is consistent with and potentially explains the mixed empirical evidence

hospital quality choice and market structure in a regulated duopoly this paper analyzes the optimal structure of a regulated health care industry in a model in which the regulator cannot enforce what hospitals do unverifiable quality of health or does not know what hospitals know incomplete information about production costs or both we show that if quality is unverifiable the choice between monopoly and duopoly does not change with respect to the verifiable case but if there are fixed costs assumed to be quality dependent and the monopoly is the optimal market structure the quality level of the operative hospital decreases asymmetry of information introduces informational rents that can be reduced by increasing the most efficient hospital s market share a monopoly is chosen more often

quality and outside capacity in the provision of health services abstract this paper studies the effects of non contractibility of investment on the choices made by a health authority and a hospital which supplies a specific service non contractibility determines inefficiencies compared with any pareto efficient outcome the quality of the service chosen by the hospital is too low and the health authority relies too much on outside providers

capital accumulation income distribution and endogenous fertility in an overlapping generations general equilibrium model abstract this paper studies the intertemporal relationships among population growth income distribution inter generational social mobility skill composition of the labor force and household income in an overlapping generations general equilibrium model that aggregates household decisions regarding fertility savings and investment in human capital of children it shows that as a consequence of endogenous fertility the equilibrium path attains steady state from the second generation income tax transfer child taxation and social security taxation policies that can be devised to affect these variables are also analyzed the model provides a structural explanation for the inverse household income child quantity and negative child quality quantity relationships that are observed in developing countries it also shows that group interests may hinder the emergence of perfect capital markets with private initiatives

from malthus to modern growth can epidemics explain the three regimes we model demographic and economic long run development in a setting where mortality is endogenous and subject to epidemic shocks the model replicates the full transition from malthusian stagnation to modern growth consistent with the historical facts the economy also passes an intermediate post malthusian phase where growth rates of both population and per capita income increase simultaneously as mortality rates fall and become less volatile the escape from the malthusian trap is the result of a series of mild epidemic shocks making it inevitable at some stage but its timing random calibrations show that it can differ by thousands of generations absent differences in exogenous parameters

mortality decline human capital investment and economic growth abstract we examine the role of increased life expectancy in raising human capital investment during the process of economic growth we develop a continuous time overlapping generations model in which individuals make optimal schooling investment choices in the face of a constant probability of death we present analytic results followed by results from a calibrated version of the model using realistic estimates of the return to schooling mortality decline produces economically significant increases in schooling and consumption allowing schooling to vary endogenously produces a much larger response of consumption and capital to mortality decline than is observed when schooling is held fixed

deregulation and quality abstract this paper analyses within a static model the effect of quality concern on optimal market structure it focuses on cases where industry quality has public good like features and is not contractible it is shown that the introduction of competition raises a free rider problem which depresses quality the smaller producer free rides on its competitor investment which as a result underinvests to encourage the efficient producer to provide quality the regulator diminishes the market share of the opportunistic producer and chooses more often a monopoly however when quality is verifiable the introduction of competition entails no welfare loss whether the regulator observes total quality outcome or individual contributions

a complete solution to a class of principal agent problems with an application to the control of a self managed firm this paper considers a class of principal agent problems which have the following features 1 there is adverse selection because the principal ignores the value of one parameter of the agent s true characteristics 2 leaving aside the information parameter the principal s welfare as well as the agent s welfare depend on two types of variables observable to both of them the first ones possibly multidimensional are called action variable s and the second one which is one dimensional has in general the meaning of a money transfer 3 the principal is a stackelberg leader of the two person game he can commit himself to decision rules which are admissible on informational grounds he optimizes within the adequate class taking into account besides the agent s reaction one constraint which has generally the meaning of an individual rationality constraint and sometimes of a feasibility constraint the optimization is limited to the class of non stochastic mechanisms 4 the problem can also receive an alternative interpretation the principal faces a continuum of agents of unknown characteristics the distribution being known however stylized principal agent problems of this type have often been considered in the economic literature in particular the reader will later be able to recognize that the standard income tax model a la mirrlees 1971 the quality or quantity choice model of the monopolist a la mussa and rosen 1978 or maskin and riley 1982 and the model of government regulation of the private monopolist of baron and myerson 1982 all belong to

the existence of perfect equilibria in a model of growth with altruism between generations an intertemporal model of consumption and bequest behaviour is specified and analysed as a game between generations the main feature of this game is that no a priori restrictions like linearity are placed on the strategy choice of generations the paper gives an existence proof for perfect nash equilibria in finite and infinite horizon versions of the model and determines characteristic properties of equilibrium strategies the main result is to demonstrate existence of stationary perfect equilibrium if the time horizon is infinite

the old age security hypothesis revisited abstract children s altruism toward parents is allowed in a two overlapping generations model with endogenous fertility parents raise children because when retired they expect gifts from their children who are essentially a capital good individuals behavior between generations is examined by analyzing a nash equilibrium which is then compared with a social planner s optimal allocation the pay as you go public pension program is viewed as the optimal gifts from the optimal allocation when the latter is implemented the effect on fertility of the introduction of a capital market is also analyzed the validity of the old age security hypothesis is shown to depend on the parameters of utility and cost functions

social security and endogenous growth abstract this paper examines the effects of social security on the steady state growth of per capita income in an endogenous growth model in which agents care about their own consumption the number of children and the welfare of each child it shows that an unfunded program may simulate growth by reducing fertility and increasing the ratio of human capital investment per child to per family income when bequests are positive also it may cause faster growth than funded programs especially when receipts from funded programs are independent of contributions when voluntary saving is positive funded social security is neutral if receipts are linked to contributions and most likely depresses growth if receipts are independent of contributions

motives for private income transfers private income transfers are becoming increasingly recognized as a key aspect of the u s economy the majority of private income transfers occur inter vivos i e between living persons but very little is known about this type of transfer behavior this paper tests alternative hypotheses concerning motivation for inter vivos transfers two motives are considered altruism and exchange evidence presented here casts doubt on the altruistic model of transfer behavior observed patterns for inter vivos transfers are more consistent with exchange related motives this finding has important implications for the effects of public transfer programs on the distribution of economic well being

the family inheritance and the intergenerational transmission of inequality unequal inheritance of material wealth is commonly considered a major cause of inequality in consumption however theoretical models of the intergenerational transmission of inequality by becker blinder and ishikawa imply that unequal inheritance may either increase or reduce consumption inequality differences in inherited wealth resulting from unequal parental incomes increase inequality in recipients consumption however unequal bequests caused by differences among families in the endowed ability of children or the costs of producing human capital are equalizing empirical results confirm these predictions the inheritance received by children is inversely related to both children s income and parental education thus bequests are compensatory in that ceteris paribus low income children inherit more than their advantaged contemporaries

life expectancy and endogenous growth we consider an overlapping generations model with uncertain lifetime and endogenous growth individuals have to choose the length of time devoted to schooling before starting to work we show that it depends positively on life expectancy but that the positive effect of a longer life on growth could be offset by a decrease in the participation rate dynamics are characterized by a delay differential equation and human capital converges with oscillations to a balanced growth path

an econometric analysis of the old age security motive for childbearing a switching regression for birth interval lengths with endogenous switching is developed to test mead cains contention that parents fertility decisions arise from lexicographic preferences for old age security the model is estimated as a survival model using malaysian data assuming that contraceptors constitute the group of parents who have attained the minimal number of children with which they feel their old age support is secure strong support for cains concept of old age security as the principal interest of those parents who have not yet attained a sufficient number of children appears in these data however the income effect accompanying the provision of alternative means of old age support generates an ambiguous effect on subsequent fertility excerpt

endogenous fertility and optimal population size pareto optimality which is the standard criterion of efficiency in general equilibrium models takes population size as given and therefore cannot be directly applied to analyze the question of optimal population size the criterion then for optimal population size must be based on a more restrictive definition of optimality this paper extends peter diamonds 1965 golden golden rule growth model by assuming that individuals derive utility from their own consumptionand from their own children offspring are assumed to consume resources before reaching adulthood the authors show that the optimal steady state utility yields a higher population growth rate when it converges to the golden rule allocation they then demonstrate that a voluntary social security program in which the size of the transfer to a particular agent is directly tied to his own fertility leads the competitive allocation to be identical to the allocation corresponding to the maximum of the steady state utility of the representative individual

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

bequest motives social security and economic growth junxi zhang this article conducts a systematic analysis of four bequest motives in a simple model of endogenous growth it analyzes how bequest motives affect fertility savings growth and the effects of pay as you go social security it is found that altruistic and exchange motives give equivalent outcomes if the discount factors are set the same the outcome under the joy of giving motive may involve a higher bequest ratio higher saving and better growth rates than that under altruism if bequests are accidental the equilibrium values will depend on the probability of survival moreover the results provide testable implications on bequest motives jel d1 d9 h55 j1 i introduction although the importance of bequests in aggregate savings has been established by kotlikoff and summers 1981 who reported that 80 of u s household wealth is inherited wealth what bequest motives lead to inheritance remains an unsolved problem yet it is well known that bequest motives have important implications for the behavior of financial markets the macroeconomic impacts of fiscal policies and the intergenerational transmission of inequality in the distribution of wealth at least four hypotheses for the existence of bequests have been discussed in the literature 1 bequests may arise from intergenerational altruism that is parents obtain utility from their heirs utility as well as from their own consumption barro 1974 2 the prospect of bequests is used by parents to induce children to behave as desired by parents bernheim et al 1985 3 bequests may arise from the joy of giving that is parents leave bequests simply because they obtain utility directly from the bequest yaari 1964 1 and 4 bequests may be the unintentional by product of precautionary savings and a stochastic date of death in the absence of an annuity market abel 1985 following barro 1974 and becker 1974 the altruistic bequest motive has been used most frequently however the enormous empirical work using micro data has not led to conclusive evidence on the one hand bernheim et al 1985 cox 1987 and cox and rank 1992 show that bequests are more consistent with exchange than altruism altonji et al 1992 1997 also show that altruism is decisively rejected moreover wilhelm 1996 finds little support for an altruistic theory of bequests on the other hand a recent reexamination of the exchange motive by perozek 1998 shows that the finding of bernheim et al is not robust laitner and juster 1996 find some evidence of altruistic bequests therefore a definite conclusion on bequest motives seems far from over indeed though altruism has not been supported by most of those empirical studies it remains a plausible hypothesis and continues to be used frequently see e g coate 1995 and davies and zhang 1995 abel 1985 argues theoretically that although the simple life cycle model without bequest motives is an inadequate description of the savi ng behavior in the united states as found in kotlikoff and summers 1981 accidental bequests by selfish consumers can account for a sizable fraction of aggregate wealth however little formal empirical work has been done to test whether bequests are accidental or arise from joy of giving given the lack of consensus on bequest motives it is interesting to conduct a systematic theoretical analysis of different bequest motives in a particular context becker et al 1990 and caballe 1995 assume altruism in their models of economic growth wiedmer s 1996 analysis of social security and growth does not consider bequests except ihori 1994 there seems to be no analysis of other bequest motives in the context of economic growth the purpose of this article is to analyze how different bequest motives affect fertility savings and economic growth the article will also examine how the effects of pay as you go social security depend on bequest motives

competition and quality in health care markets a differential game approach we investigate the effect of competition on quality in health care markets with regulated prices taking a differential game approach in which quality is a stock variable using a hotelling framework we derive the open loop solution health care providers set the optimal investment plan at the initial period and the feedback closed loop solution providers move investments in response to the dynamics of the states under the closed loop solution competition is more intense in the sense that providers observe quality in each period and base their investment on this information if the marginal provision cost is constant the open loop and closed loop solutions coincide and the results are similar to the ones obtained by static models if the marginal provision cost is increasing investment and quality are lower in the closed loop solution when competition is more intense in this case static models tend to exaggerate the positive effect of competition on quality

competition and equity in health care markets we provide a model where hospitals compete on quality under fixed prices to investigate how hospital competition affects i quality differences between hospitals and as a result ii health inequalities across hospitals and patient severities the answer to the first question is ambiguous and depends on factors related to both demand and supply of health care whether competition increases or reduces health inequalities depends on the type and measure of inequality health inequalities due to the postcode lottery are more likely to decrease if the marginal health gains from quality decrease at a higher rate whereas health inequalities between high and low severity patients decrease if patient composition effects are sufficiently small we also investigate the effect of competition on health inequalities as measured by the gini and the generalised gini coefficients and highlight differences compared to the simpler dispersion measures

intergenerational transfers and demographic transition abstract this paper presents an analysis of demographic transition based on the endogenous evolution of intergenerational transfers along an economy s endogenous path of development two period lived agents belonging to overlapping generations choose optimally their desired levels of consumption and fertility together with their desired sizes of transfers to both parents and children parents are more efficient than children in producing output but some parental time must be devoted to child rearing at low levels of development fertility is high and the flow of net intergenerational transfers is from the young to the old at high levels of development fertility is low and the flow of net transfers is from the old to the young these results accord strongly with empirical observations and the analysis may be seen as formalising for the first time a long standing and well respected hypothesis in the demographic transition literature

regulating a monopolist with unknown costs we consider the problem of how to regulate a monopolistic firm whose costs are unknown to the regulator the regulator s objective is to maximize a linear social welfare function of the consumers surplus and the firm s profit in the optimal regulatory policy prices and subsidies are designed as functions of the firm s cost report so that expected social welfare is maximized subject to the constraints that the firm has nonnegative profit and has no incentive to misrepresent its costs we explicitly derive the optimal policy and analyze its properties in their classic papers dupuit 2 and hotelling 5 considered pricing policies for a bridge that had a fixed cost of construction and zero marginal cost they demonstrated that the pricing policy that maximizes consumer well being is to set price equal to marginal cost and to provide a subsidy to the supplier equal to the fixed cost so that a firm would be willing to provide the bridge this first best solution is based on a number of informational assumptions first the demand function is assumed to be known to both the regulator and to the firm while the assumption of complete information may be too strong the assumption that information about demand is as available to the regulator as it is to the firm does not seem unnatural a second informational assumption is that the regulator has complete information about the cost of the firm or at least has the same information about cost as does the firm this assumption is unlikely to be met in reality since the firm would be expected to have better information about costs than would the regulator as weitzman has stated an essential feature of the regulatory environment i am trying to describe is uncertainty about the exact specification of each firm s cost function in most cases even the managers and engineers most closely associated with production will be unable to precisely specify beforehand the cheapest way to generate various hypothetical output levels because they are yet removed from the production process the regulators are likely to be vaguer still about a firm s cost function 12 p 684 as this observation suggests it is natural to expect that a firm would have better information regarding its costs than would a regulator the purpose of this paper is to develop an optimal regulatory policy for the case in which the regulator does not know the costs of the firm one strategy that a regulator could use in the absence of full information about costs is to give the firm the title to the total social surplus and to delegate the pricing decision to the firm in pursuing its own interests which would then be to maximize the total social surplus the firm would adopt the same marginal cost pricing strategy that the regulator would have imposed if the regulator had

incomplete information and optimal market structure public purchases from private providers abstract market structure is endogenized in a normative model of public procurement featuring a social cost of profit product variety economies of scale and incomplete information about cost depending on parameters either sole sourcing or dual sourcing might be optimal however if the social cost of profit is positive but not too large incomplete information biases optimal market structure in favor of sole sourcing on the other hand this bias in favor of sole sourcing may be reversed if the social cost of profit is large an application to the publicly financed treatment for drug abuse motivates the analysis

social security intergenerational transfers and endogenous growth in this paper the effects of social security in a simple model of endogenous growth with alternative motives of having children are analyzed it shows how the effects of social security depend on the size of the social security tax the motive to have children and the pattern of intergenerational transfers the pattern of intergenerational transfers itself however is shown to change with the social security tax rate when the social security tax is not too high social security increases per capita income growth and tends to enhance welfare