the effects of fiscal policies when incomes are uncertain a contradiction to ricardian equivalence this paper shows that when future earnings are uncertain the substitution of deficit fin ance for tax finance or the introduction of an unfunded social secur ity program can raise consumption even if all bequests reflect inter generational altruism an operative bequest motive therefore need not imply ricardian equivalence this conclusion follows from the result derived in the paper that the uncertainty of future income makes t he existence of a future bequest uncertain to the prospective donor copyright 1988 by american economic association

social security liquidity constraints and pre retirement consumption one of the primary goals of the social security retirement program is the maintenance of consumption in old age in the past decade since the pioneering paper by feldstein 13 studies have examined the impact of the system on consumption over the entire life cycle and not just in old age empirical work has tested the impact on consumption of the individual wealth transfers accompanying the introduction of a pay as you go social security system extending this discussion of the impact of social security on pre retirement consumption hubbard 21 has shown in the context of lifetime uncertainty that even an actuarially fair fully funded social security system can raise lifetime consumption hence previous partial equilibrium estimates of the impact of social security on consumption drawn solely from consideration of the intergenerational wealth transfer at the introduction of the system are underestimates of the potential effect 2 an important assumption in the approaches cited above is that of perfect capital markets i e that individuals can borrow against prospective gains from participating in the social security system such an assumption is at variance with actual limitations on borrowing e g upward sloping interest rate schedules collateral requirements and quantity restrictions hayashi 18 found that approximately twenty percent of all consumption in the u s is accounted for by liquidity constrained consumers 3 flavin 16 found that the estimate of the marginal propensity to consume is affected dramatically by the inclusion of proxies for liquidity constraints suggesting that liquidity constraints are an important part of the observed excess sensitivity of consumption to current income since its inception in 1935 old age and survivors insurance oasi provided

north american money surprises and financial market reactions an empirical note abstract in the late 1970s u s and canadian weekly money supply announcements occurred almost simultaneously the unanticipated components of these announcements are shown to be correlated and the importance of this factor for findings in the money surprise market response literature is explored

the effect of annuity insurance on savings and inequality this paper examines the amount of precautionary savings and wealth inequality arising from life span uncertainty by comparing saving behavior under perfect insurance arrangements with that arising under imperfect arrangements namely when longevity risk can be pooled only with members of one s own family the central findings of the paper are that 1 perfecting insurance arrangements can sharply lower savings in both intergenerationally altruistic and life cycle economies and that 2 in altruistic economies perfecting annuity insurance can greatly influence inequality indeed in the long run in our model switching from imperfect family insurance to perfect insurance can mean the difference between absolute inequality and absolute equality

exchange rates interest rates and current account news some evidence from australia abstract this paper investigates the effects of the australian current account news on exchange rates and interest rates for the period july 1985 to december 1992 the results indicate that the australian dollar depreciated and interest rates rose as a result of an announcement of a larger than expected current account deficit this is consistent with the view that market participants expected a foreign exchange market intervention sale of the australian dollar by the reserve bank of australia and they used the portfolio balance model of exchange rate determination when responding to the news in addition significant structural breaks were found and the analysis shows that after january 1990 the news affected neither exchange rates nor interest rates

the effect of annuity insurance and savings and inequality this paper examines the amount of precautionary savings and wealth inequality arising from life span uncertainty by comparing saving behavior under perfect insurance arrangements with that arising under imperfect arrangements namely when longevity risk can be pooled only with members of one s own family the central findings of the paper are 1 perfecting insurance arrangements can lower savings in intergenerationally altruistic and life cycle economies and 2 in altruistic economies perfecting annuity insurance can influence in equality indeed in the long run in the model switching from imperfect family insurance to perfect insurance can mean the difference between absolute inequality and absolute equality copyright 1986 by university of chicago press

social security life insurance and annuities for families abstract in this paper we ask whether an aspect of social security namely its role as a provider of insurance against uncertain life spans is welfare enhancing to this end we use an olg model where agents have a bequest motive and differ in sex and marital status and where families are formed and destroyed and their characteristics evolve exogenously according to u s demographic patterns of marriage divorce fertility and mortality we compare the implications of social security under a variety of market structures that differ in the extent to which life insurance and annuities are available we find that social security is a bad idea in economies where the private sector provides annuities and life insurance it is a bad idea for the standard reason that it distorts the intertemporal margin by lowering the capital stock in the absence of such securities social security is still a very bad idea only marginally less so compared with economies with annuities and life insurance we also explore these issues in a world where people live longer and we find no differences in our answers as a by product of our analysis we find that the existence of life insurance opportunities for people is important in welfare terms while that of annuities is not

the effect of social security on the steady state distribution of consumption abstract abel has shown that the introduction of a fully funded social security ss would decrease the variances of the steady state distribution of young period and old period consumptions eckstein et al have shown that a perfect ss would increase the steady state expected utility of consumptions we intend to give a caveat on their positive results by showing that the assumptions from which the above propositions are derived have some unrealistic implications and that by replacing these assumptions with more reasonable ones we may obtain very different results the only positive conclusion we are certain of is that a marginal ss insurance in the no insurance situation can always reduce the steady state coefficient of variation of both young and old period consumption distributions

health investment saving and public policy this paper develops an overlapping generations model in which agents invest in health to prolong life in both working and retirement periods it explores how unfunded social security with or without health subsidies affects life expectancy economic growth and welfare in particular by extending life at a possible cost of capital accumulation health subsidies and a pay as you go pension can improve welfare especially in the short run

aggregate and distributional effects of fair social security abstract in an overlapping generations economy with production endogenous labor supply a bequest motive and uncertain lifetime we show that a fair fully funded social security program reduces the aggregate levels of output employment capital and savings we determine the necessary and sufficient conditions for this social security program to increase the inequality of the income distribution the conclusions apply to the entire non stationary competitive equilibrium path taken by the economy following the introduction of social security

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

economic surprises and the behaviour of asset prices some analyses and further empirical results this paper examines the implications of serial correlation in asset prices for market efficiency and announcement effect tests the impact of four types of economic surprise is examined after allowing for observed serial correlation in three asset price series

government intervention as a bequest substitute abstract a subsequent generations model is used in order to characterize consumption allocation under the future generation s income uncertainty altruistic concerns towards future generations give rise to precautionary bequests which act as a hedge on risk it is shown that given a first order correlation between mean future income and the present generation s income government can provide a pareto improvement through a tax transfer policy with universal participation this policy acts as a substitute for precautionary bequests distributional aspects of government tax transfer policy are also discussed

unemployment insurance and precautionary saving abstract models of precautionary saving imply that households will hold more assets when faced with greater income uncertainty however previous empirical studies of income uncertainty have produced somewhat mixed support for the precautionary saving hypothesis in this paper we note that differences in the state contingent income stream available to workers through the unemployment insurance ui program provides an excellent source of variation for testing the presence of a precautionary savings motive simulations of a stochastic life cycle model suggest that a ui system similar to the type currently in place in the u s can lead to a significant reduction in the assets accumulated by a median worker moreover there is considerable variation in the ui benefit schedules for workers living in different states in the u s which provides an exogenous source of variation for empirically testing the precautionary saving hypothesis we carry out this test using data on expected ui benefit replacement rates and financial assets held by households in the survey of income and program participation our empirical results are consistent with the predictions of the model and suggest that reducing the ui benefit replacement rate by 50 percent would increase gross financial asset holdings by 14 percent or 241 for the average worker we also find empirical evidence that this crowd out effect of ui on household saving is stronger for those facing higher unemployment risk and weaker for older workers both of which are implications from our precautionary saving model

income uncertainty and the demand for annuities abstract two well known results concerning the demand for annuities in an overlapping generations model are i egoistic agents should annuitize all their wealth and ii altruistic agents should segment their savings between riskless bonds for bequests and annuities for own consumption this paper extends the analysis by considering income uncertainty it is shown that while the segmentation result holds under future generation s income uncertainty fgiu altruistic agents do not segment their savings in the presence of second period income uncertainty spiu the intuition for this result is that income uncertainty in the second period of life is contingent on being alive and therefore at the optimum the covariance between one s offspring s consumption and life uncertainty is not zero as in the case of certainty and fgiu the effects of precautionary savings on the demand for annuities are also analyzed

uncertainty and the neutrality of government financing policy abstract some ideas from the theory of finance are applied to consider whether debt financed tax cuts affect desired consumption it is shown that government financing policy is a matter of indifference to infinitely lived households if a perfect substitute for public debt exists the analysis allows for uncertainty about future taxes and for missing markets in some kinds of assets income redistribution risk and the public insurance aspects of an income tax scheme qualify this neutrality result but in general the net effect is ambiguous the real resource costs of financial transacting as well as government superiority in the intermediation process may be one rationale for activist debt management policy a better understanding of functioning capital markets is essential to evaluate these arguments

quasi hyperbolic discounting and social security systems hyperbolic discounting has become a common assumption for modeling bounded rationality with respect to individual savings decisions we examine the effects of hyperbolic discounting on the comparison of alternative social security systems we show that this form of bounded rationality breaks the equivalence between funded and pay as you go systems established in sheshinski and weiss 1981 intergenerational transfers within a payg economy are usually secured by the social security system and independent of longevity whereas this is not the case for the funded economy the savings level under hyperbolic discounting is lower than under exponential discounting laibson et al 1996 but the ratio between the savings level under hyperbolic discounting within a funded economy and a payg economy depends on the effectiveness of the commitment devices it is shown that if individuals are hyperbolic discounters then in a payg economy any change in the mandated level of intergenerational transfers is neutralized by individuals voluntary bequests this does not apply to a funded system

optimal long run fiscal policy constraints preferences and the resolution of uncertainty we construct a computational dynamic stochastic overlapping generations general equilibrium model with uncertain lifetimes and explore the impact of policy stickiness specifically a major reform will preclude future reforms for a generation on optimal long run fiscal policy under such circumstances entitlement reforms exhaust a valuable option to move in the future we explore the conditions under which the gain to waiting is large enough to induce optimizing policymakers to delay reforming a suboptimal system we also allow for the uncertainty to have arch characteristics and explore the impact of time varying uncertainty on the optimality of delayed policy action

is everything neutral in his well known analysis of the national debt robert barro introduced the notion of a dynastic family this notion has since become a standard research tool particularly in the areas of public finance and macroeconomics in this paper we critique the assumptions on which the dynastic model is predicated and argue that this framework is not a suitable abstraction in contexts in which the objective is to analyze the effects of public policies we reach this conclusion by formally considering a world in which each generation consists of a large number of distinct individuals as opposed to one representative individual we point out that family linkages form complex networks in which each individual may belong to many dynastic groupings the resulting proliferation of linkages between families gives rise to a host of neutrality results including the irrelevance of all public redistributions distortionary taxes and prices since these results are not at all descriptive of the real world we conclude

comment on kotlikoff shoven and spivak in the absence of perfect annuity markets individual consumers generally undertake precautionary saving to provide resources for their future consumption in the event that they live longer than expected kotlikoff shoven and spivak in this issue hereafter kss have provided us with a well conceived and well executed study of the effects of various annuity arrangements on individual and aggregate saving in the presence of lifetime uncertainty each of these authors has had a long standing interest in this area and their current paper reflects their accumulated expertise their results indicate that a potentially sizable fraction of u s household wealth represents precautionary saving resulting from the absence of perfect annuity markets the strategy of the kss paper is to develop simple models of individual saving behavior on the basis of utility maximization and then to aggregate the behavior of individuals both intraand intertemporally by comparing the results of models that differ in the specification of bequest motives and opportunities for creating annuities kss provide insights about the effects of various annuity arrangements on saving and capital accumulation although the models are all conceptually simple analytic solutions cannot be obtained in many cases therefore kss provide numerical solutions to their models in addition because the models are conceptually

precautionary savings and the self employed this work focuses on the impact of uncertainty on savings under bequest form specifically we estimate whether and to what extent income variability does have an effect on post mortem savings we approximate the post mortem savings with the closest dedicated savings which is savings in term insurance a lump sum inherited at the death of the subscriber furthermore we test whether the intensity of the income variance or the riskiness of the job type such as self employment matters more in the choice our results show that self employment status is one of the most relevant variables affecting term insurance ownership

the family as an incomplete annuities market families can self insure against uncertain dates of death through implicit or explicit agreements with respect to consumption and interfamily transfers interfamily transfers need have nothing to do with altruistic feelings they may simply reflect risk sharing behavior of completely selfish family members although family annuity markets are incomplete even small families can substitute by more than 70 percent for perfect market annuities given adverse selection and transaction costs family risk pooling may be preferred to public market annuities in the absence of public annuities these risk sharing arrangements provide powerful incentives for marriage and family formation

intergenerational aspects of public transfers borrowing and debt the paper analyzes intergeneration distributional effects of taxes transfer payments public borrowing and debt a two period life cucle model with overlapping generations is constructed the model has two specific features private wealth in both periods enter as arguments in the preference function and the individuals inelastically supply labor in both periods it turns out that some fiscal policy actions favor both of the currently lliving generations possibly at the expense of future generations while other actions generate conflicts between the currently living generations the analysis also shows that it makes considerable difference whether the burden of public spending debt and borrowing is defined in terms of wealth consumption and utility the different implications of foreign vs domestic debt are examined

assessing ricardian equivalence this paper reviews the literature on ricardian equivalence this hypothesis may be interpreted as a generalisation to the short and the long run of the theories which put no weight on the real effects of public policies on aggregate demand we argue that ricardian equivalence relies on both permanent income hypothesis and the fulfilment of the intertemporal government budget constraint the theoretical literature emphasises several reasons for departures from this hypothesis however the empirical literature is inconclusive when ricardian equivalence is tested in a life cycle framework the hypothesis is usually rejected while when the empirical analysis is based on optimising models it is usually accepted

on barro s theorem of debt neutrality the irrelevance of net wealth the effects of national debt on real economic activity has been a recurring topic in the literature on macroeconomic policy analysis since the time of adam smith the problem is usually stated as follows for a given level of government spending is the economy sensitive to the financing mix between tax and debt historically attention has focused on the question of whether or not individuals perceive government bonds as net wealth the link between wealth and real activity being taken as given the main point of debate is well established the issue of bonds raises private assets by the full value of the bonds the corresponding tax liabilities for interest payments and retirement of the debt extend indefinitely into the future the perception of bonds as net wealth would then appear to depend on the length of the individual s optimization horizon the most recent contribution to this debate was made by robert barro 1974 in which he argued that despite the limitation of finite lives bonds will not be regarded as net wealth in a system characterized by operative intergenerational transfers the essence of his argument is that inclusion of a bequest motive effectively converts a finite horizon into an infinite one in that paper barro acknowledged a potential limitation on his proof of the neutrality result it was only valid for bonds that are redeemed at a known point in the future this limitation was raised again in a subsequent exchange with martin feldstein in which barro 1976 agreed that for a growing economy an increase in steady state per capita debt will generate net wealth if the rate of growth is greater than the interest rate however he argued that such a steadystate growth situation would not be consistent with rational utility maximizing behavior the main theme of this paper is that the literature has focused attention on the wrong question the real effects of national debt are independent of whether or not individuals perceive the debt as net wealth the correct question is whether or not changes in the level of debt force individuals into patterns of intertemporal consumption that they are unable to neutralize by adjustments in their portfolio behavior viewing neutrality in this light leads to some reinterpretation of the conditions under which neutrality is likely to hold my analysis starts where barro and feldstein leave off within the framework of the overlapping generations model with gift and bequest motives i show that steady state equilibrium growth is consistent with a growth rate in excess of the interest rate indeed without specific knowledge of the parameters of the economy there are no a priori grounds on which to expect any particular relationship between the growth and interest rates more importantly so long as it is valid to view the aggregate economy as behaving like a composite individual changes in the steady state level of government debt are neutral regardless of which relationship prevails provided one or the other of the intergenerational transfer motives is operative i will refer to this as the extended neutrality theorem section i presents an analysis of steadystate growth with gift and bequest behavior the steady state growth path is shown to lie above the golden rule solution if the gift

the failure of ricardian equivalence under progressive wealth taxation abstract although the ricardian equivalence theorem holds under a linear estate tax schedule it fails to hold under a nonlinear estate tax schedule in a representative consumer economy a temporary lump sum tax increase reduces contemporaneous consumption if different consumers face different marginal estate tax rates because they leave bequests of different sizes a lump sum tax increase redistributes resources from consumers in low marginal estate tax brackets to consumers in high marginal estate tax brackets aggregate consumption may rise fall or remain unchanged these departures from ricardian equivalence hold more generally under any nonlinear tax on saving wealth or income accruing to wealth

pay as you go social security and the distribution of altruistic transfers this paper studies the impact of an unfunded social security system on the distribution of altruistic transfers in a framework where savings are due to both life cycle and random altruistic motivations we show that the effect of social security on the distribution of these transfers depends crucially on the strength of the bequest motive in explaining savings behaviour we measure this strength by the expected weight that individuals attach to the utility of future generations on the one hand if the bequest motive is strong then an increase in the social security tax raises the bequests left by altruistic parents on the other hand when the importance of altruism in motivating savings is sufficiently low the increase in the social security tax could result in a reduction of the bequests left by altruistic parents under some conditions on the attitude of individuals toward risk and on the relative returns associated with private saving and social security some implications concerning the transitional effects of introducing an unfunded social security scheme are also discussed

social insurance and the optimum piecewise linear income tax abstract this paper calculates optimal linear income taxes when differences in income are caused by random factors luck rather than by unobserved individual skills as assumed in the classical theory of income taxation as first shown by varian 1980 varian h r 1980 redistributive taxation as social insurance journal of public economics 14 49 68 in the former case income taxation acts as social insurance by introducing life uncertainty and precautionary behavior we find higher optimal marginal tax rates than those found by varian we also find that in the context of a piecewise two bracket linear tax schedule the second marginal tax is higher than the first a finding that contrasts with results recently obtained in the framework of classical income taxation theory which show a lower second marginal tax

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

deutsche mark dollar volatility intraday activity patterns macroeconomic announcements and longer run dependencies this paper provides a detailed characterization of the volatility in the deutsche mark dollar foreign exchange market using an annual sample of five minute returns the approach captures the intraday activity patterns the macroeconomic announcements and the volatility persistence arch known from daily returns the different features are separately quantified and shown to account for a substantial fraction of return variability both at the intraday and daily level the implications of the results for the interpretation of the fundamental driving forces behind the volatility process is also discussed the efficient market hypothesis contends that financial asset prices provide rational assessments of fundamental values and future payoffs by implication price changes should reflect the arrival and processing of all relevant new information however the proportion of return variability that can be ascribed to public news announcements is low for example cutler poterba and summers 1989 find that even the largest daily price changes in the stock market generally cannot be associated with any significant economic news 1 moreover proxies for the flow of public information e g the number of news items released by reuter s news service berry and hiowe 1994 or dow jones company mitchell and mulherin 1994 explain little of the overall variation thus if private information is ruled out proponents of rational price formation have to assert the existence of important news items

social security and unsecured debt abstract in this paper we use a calibrated life cycle model to explore quantitatively ways of reducing the burden of social security in a world populated by both optimizing and rule of thumb consumers social security contributions force young households with upward sloping income profiles to save a sizeable portion of their income for retirement when their optimal consumption plan would likely have them either saving little or borrowing we first use household data to document that young households have accumulated social security contributions that are large relative to debt holdings then using a calibrated life cycle model we show that both allowing households to use social security wealth to pay off their debt and exempting young households from social security contributions but in both cases requiring higher contributions later mitigate many of the inefficiencies of social security from the perspective of life cycle financial planning specifically in our preferred experiment which exempts households whose heads are under 30 from making social security contributions we find that certainty equivalent consumption increases by 3 4 for optimizing households and by 3 3 for rule of thumb households

income uncertainty bequests and annuities abstract life uncertainty and income uncertainty are modeled simultaneously in order to analyze the influence of perfecting income insurance in the size of bequests and the demand for annuities the main result shows that government intervention aimed at providing intergenerational risk sharing acts as a bequest substitute and if annuities are available reduces the demand for annuities

intergenerational risk sharing abstract in this paper we examine government debt and tax transfer policies that can be improve the allocation of risk between generations markets cannot allocate risk efficiently between two generations whenever the two generations are not both alive prior to the occurence of a stochastic event this implies that government policies transferring risk between generations have the potential to create first order welfare improvements our model provides a non keynesian justification for the debt finance of wars and recessions as well as an added rationale for social security type tax transfer schemes which aid unlucky generations e g the depression generation at the expense of luckier generations

domestic macroeconomic news and foreign interest rates abstract this study examines the impact of us and uk news on futures prices of us uk german and japanese government bonds we find that certain us information has a significant influence on german japanese and british interest rates while uk information has almost no effect on foreign rates second we examine the foreign term structure to investigate whether the importance of us information arises because it either signals common world wide shocks or induces an anticipated exchange rate stabilization by foreign central banks the evidence is mixed except for the us cpi surprise which appears to provide information about a common world wide shock g15

estate taxation with intended and accidental bequests abstract in this paper we examine the properties of the optimal estate tax in the presence of a complete set of tax instruments available to the social planner we allow for both types of bequest motives namely altruistic and accidental we examine the case for estate taxation which seems to be the strongest but not impeccable with accidental bequests in general the estate tax is highly sensitive to the relative importance of the two bequest motives

rationalizable strategic behavior the notion of equilibrium proposed by nash 19 has come to play a dominant role in economic applications of noncooperative games while analyses of nash equilibria have unquestionably contributed to our understanding of economic behavior it would be unreasonably optimistic to maintain that nash solved the problem of noncooperative strategic choice there is a small literature beginning with ellsberg 6 and a much larger oral tradition which argues that nash behavior is neither a necessary consequence of rationality nor a reasonable empirical proposition in this paper i take the view that although there may be various reasons why an agent might select a nash strategy the notion of an equilibrium has little intrinsic appeal within a strategic context when an agent reaches a decision in ignorance of the strategies adopted by other players rationality consists of making a choice which is justifiable by an internally consistent system of beliefs rather than one which is optimal post hoc this point of view is not original indeed most serious justifications of the nash hypothesis embrace such an approach arguing that agents will expect the game to yield a nash outcome and consequently will choose their equilibrium strategies nevertheless when we think in terms of maximizing utility subject to expectations rather than realizations it becomes clear that the nash hypothesis far from being a consequence of rationality arises from certain restrictions on agents expectations which may or may not be plausible depending upon the game being played we are then quite naturally led to ask are there any restrictions of individuals expectations and hence choices which are required by rationality alone rather than by subjective plausibility this paper is concerned with defining justifying characterizing and refining a criterion for rational strategic choice which i label rationalizability

population uncertainty social insurance abstract uncertainty in the size of the working population leads to uncertainty in wages and in the return to capital and to the possible desirability of an insurance contract between unborn workers and future retirees however green 1977 1988 finds that an insurance contract is unlikely to benefit both generations we show that a worker has two potential sources of actuarial bias green s result is due to workers in his model being of different types and some workers having only one source of bias a representative worker must have both sources of bias and an insurance contract will benefit both generations the results are generalized

canadian weekly money supply announcements and financial market reactions in the first years of targeting a view of market perceptions of bank of canada policy this paper demonstrates using weekly data between 1976 and 1979 that unanticipated changes in the canadian money supply exerted a significant impact on the foreign exchange and bond markets during the first years of the bank of canada s policy of targeting m1 growth this finding which is perhaps surprising in light of the apparent volatility of weekly changes in the canadian money supply is consistent with the efficient markets paradigm after the empirical regularities are established an interpretation is offered that focuses on market perceptions of the reaction function of the bank of canada

the impact of news on financial markets in the united kingdom note a number of papers see e g cornell 1983 and the references contained therein have appeared in the united states recently that examine the impact of money supply announcements on financial asset prices using the framework of the efficient markets hypothesis these studies indicate that for the united states unanticipated increases in m1 push interest rates and the exchange rate upward and place downward pressure on stock exchange prices a feature common to all these papers is that they utilize expectations data which are derived from surveying market participants rather than from a model such as an arima model in an earlier paper smith and goodhart 1985 we set out to compare the reaction of market prices to announcements made both in the united states and in the united kingdom using the dollar sterling exchange rate a price which by definition is common to both countries we found the impact of money announcements m1 in the united states and m3 in the united kingdom to be remarkably similar in magnitude however when we considered the time taken for the effect to be observed the results differed considerably whereas the u s announcement appeared to affect the exchange rate immediately the impact from the u k announcement was not felt fully until the following working day the aim of this paper is to build on these earlier results for the united kingdom this is done by considering four different financial prices along with four different announcements to ascertain the extent to which each market reacts to each announcement because we are interested not only in the magnitude of any announcement effects but also in the time taken for these effects to be fully realized the equations are estimated with the changes in the various financial prices measured over a number of alternative intervals

uncertainty and optimal social security systems this paper examines the annuity aspect of social security within the framework of an overlapping generations model the duration of life is assumed to be uncertain under a fully funded system demand for social security is determined by each generation so as to maximize expected lifetime utility taking into account the welfare of future generations under a pay as you go system with intergenerational transfers demand for retirement benefits by the working population takes into account taxes paid by descendants it is shown that the two modes of finance are equivalent in terms of all real aggregates effects of changes in expected lifetime and in the birth rate are analyzed starting at the optimal level a compulsory balanced increase in social security taxes and benefits is shown to increase short run savings

welfare and comparative statics implications of fair social security a steady state analysis abstract this paper examines the steady state welfare and comparative statics implications of fair social security in an overlapping generations model with uncertain lifetime the model is designed to capture the effects of lifetime uncertainty extending over the individual s entire lifespan the effects of intentional and unintentional bequests and the effects of the earning profile he shows that the welfare effects depend on the size of the benefits and the structure of the social security tax in particular even fair social security may have negative welfare implications if the underlying tax structure is ill designed some comparative statics implications are analyzed

rationalizable strategic behavior and the problem of perfection this paper explores the fundamental problem of what can be inferred about the outcome of a noncooperative game from the rationality of the players and from the information they possess the answer is summarized in a solution concept called rationalizability strategy profiles that are rationalizable are not always nash equilibria conversely the information in an extensive form game often allows certain unreasonable nash equilibria to be excluded from the set of rationalizable profiles a stronger form of rationalizability is appropriate if players are known to be not merely rational but also cautious what constitutes rational behavior in a noncooperative strategic situation this paper explores the issue in the context of a wide class of finite noncooperative games in extensive form the traditional answer relies heavily upon the idea of nash equilibrium nash 17 the position developed here however is that as a criterion for judging a profile of strategies to be reasonable choices for players in a game the nash equilibrium property is neither necessary nor sufficient some nash equilibria are intuitively unreasonable and not all reasonable strategy profiles are nash equilibria the fact that a nash equilibrium can be intuitively unattractive is well known the equilibrium may be imperfect introduced into the literature by selten 20 the idea of imperfect equilibria has prompted game theorists to search for a narrower definition of equilibrium while this research some of which will be discussed here has been extremely instructive it remains inconclusive theorists often agree about what should happen in particular games but to capture this intuition in a general solution concept has proved to be very difficult if this paper is successful it should make some progress in that direction the other side of the coin has received less scrutiny can all non nash profiles really be excluded on logical grounds i believe not the standard justifications for considering only nash profiles are circular in nature or make gratuitous assumptions about players decision criteria or beliefs the following discussion of these points is extremely brief due to space constraints more detailed arguments may be found in pearce 18

uncertainty resolution and the timing of annuity purchases abstract this paper considers the question of why the annuity market is thin a model is presented in which consumers have the option of purchasing annuities before discovering their survival probability they can then recontract the initial choice after the resolution of this form of uncertainty it is shown that consumers purchase insurance against their own survival probability type at a very young age and do not undertake further transactions this characterization is then used to analze the effects of introducing future income uncertainty and to investigate the trade off between old age insurance motive and portfilio flexibility

income uncertainty and ricardian equivalence this note characterizes the nature of ricardian equivalence failure when either the old generation s or the young generation s income is uncertain and the nonnegativity constraint on bequests is binding in some states of nature assuming a positive third derivative of the utility function the same condition needed for precautionary savings it is shown that the degree of failure of ricardian equivalence is greater when the corner has to do with parental poverty than when the corner has to do with children s wealth the reason is that in corners associated with parental poverty and therefore lower parental consumption marginal utility is more sensitive to extra consumption leading to a higher marginal propensity to consume in the first period consequently government transfers cause a substantial reduction of precautionary savings in poor corners in contrast to rich corners where precautionary savings are only slightly affected

adverse selection private information and lowballing in insurance markets recent contributions to the adverse selection literature have focused on a multiperiod competitive environment in this setting a clean distinction arises between the predictions of competing models cooper and hayes extend the model of rothschild and stiglitz to multiple periods the result is a self selecting equilibrium characterized by price highballing or systematically overcharging new business kunreuther and pauly suggest that information asymmetries between competing insurance firms render such price quantity policies infeasible their model results in a pooling equilibrium that is characterized by price lowballing or systematically undercharging new business our evidence is consistent with the kunreuther and pauly model and reveals the persistence of adverse selection in the automobile insurance market copyright 1990 by the university of chicago

intergenerational transfers and savings in recent years the role of intergenerational transfers in the process of wealth accumulation has been the subject of substantial empirical and theoretical analysis the key question stimulating this research is what is the main explanation for savings is it primarily accumulation for retirement as claimed by albert ando richard brumberg and franco modigliani in their celebrated life cycle model of savings is it primarily intentional accumulation for intergenerational transfers or is it primarily precautionary savings much of which may be bequeathed because of imperfections in annuity markets this paper examines a range of findings on the importance of intergenerational transfers the strong conclusion that emerges from this evidence is that intergenerational transfers play a very important if not a key role in aggregate wealth accumulation while intergenerational transfers figure very large in savings the precise motivation for such transfers is unclear intergenerational altruism might appear the most likely candidate but at least sane stylized facts such as the equal allocation of bequests among children are strongly at adds with the altruism model other explanations involving imperfect insurance arrangements or payments for child services do not appear capable of explaining the substantial amounts of transfers actually observed sorting cut the relative contributions of different models to intergenerational transfers and the precise role of intergenerational transfers in the process of wealth accumulation remains an intriguing and exciting enterprise this abstract was borrowed from another version of this item

poundm3 surprises and asset prices in this paper the relationship between unanticipated sterling m3 m3 and a variety of asset prices is investigated for part of the uk s experience with monetary targeting the unanticipated component of monetary growth is generated using money market services uk survey data and an arima model it is demonstrated that the uk survey data are rational in that they are an unbiased and efficient forecast and that the market efficiently incorporates unanticipated money growth into asset prices the sign of the unanticipated monetary component in our asset price equations tends to indicate that the fisher the inflation expectations hypothesis is better supported during the sample period

education social security and growth abstract we study the role of government s allocation of tax revenues between two outlays public investment in education a transfer to the young generation and social security benefits to the older generation in an overlapping generations economy with pay as you go social security and altruistically motivated transfers from parents to children we analyze how the allocation of the tax revenues between the two outlays affects growth and welfare in competitive equilibria a we obtain comparative dynamics results for nonstationary equilibria subject to a change in the allocation profile b for stationary equilibria we show that for a given allocation profile of the tax revenues educational subsidies can either increase the growth rate or decrease it depending on the parameters of the model preferences production function and the tax rate c if government seeks to allocate funds in a way that maximizes the growth rate we demonstrate that under some plausible conditions it is not optimal to maintain pay as you go social security however if parents preferences combine strong concern for their retirement with significant degree of altruism towards their children then pay as you go social security system does enhance growth and welfare

the distribution of wealth and welfare in the presence of incomplete annuity markets this paper examines the implications of the absence of complete annuity markets on the distribution of wealth and welfare of agents whose saving decisions are obtained under uncertainty regarding the length of their life the absence of annuities is shown to yield a unique nondegenerate intragenerational distribution of wealth which is fully characterized this characterization is then used to evaluate the pareto desirability of an annuity system alternative welfare criteria that can be used when the proposed change has differential impacts on the initial state of subsequent generations are considered

commentary nash equilibrium and mechanism design abstract i argue that the principal theoretical and practical drawbacks of nash equilibrium as a solution concept are far less troublesome in problems of mechanism design than in most other applications of game theory

anticipated inflation in a monetary economy with endogenous growth this paper makes a new attempt to investigate the role of anticipatedmonetary growth in economic growth combining the barro 1990 rebelo 1991 type endogenous growth model with sidrauski s 1967 framework we show that the pre announcement of money supply behaviour may have significant effects on the rate of growth during the transition process the key factor indetermining adjustment patterns of the economy to anticipated monetary changes is the degree of relative risk aversion however changes in the rate of monetary growth do not affect the rate of long run growth regardless of the degree of relative risk aversion

false diagnoses pitfalls of testing for asymmetric information in insurance markets established tests for asymmetric information in insurance markets are examined the most commonly used that information is symmetric if high and low cover contracts have the same loss rate is inconsistent with standard assumptions that imply that under symmetric information all contracts o er full cover incomplete cover and symmetric information can be reconciled if there are claim processing costs but now existing tests fare badly partly due to the divergence between marginal and average selection effects ignoring the nature of loading factors may cause recent studies to mismeasure the welfare costs of asymmetric information but these problems are remedial

the role of intergenerational transfers in aggregate capital accumulation this paper uses historical u s data to directly estimate the contribution of intergenerational transfers to aggregate capital accumulation the evidence presented indicates that intergenerational transfers account for the vast majority of aggregate u s capital formation only a negligible fraction of actual capital accumulation can be traced to life cycle or hump savings a major difference between this study and previous investigations of this issue is the use of more accurate longitudinal age earnings and age consumption profiles these profiles are simply too flat to generate substantial life cycle savings this paper suggests the importance of and need for substantially greater research and data collection on intergenerational transfers life cycle models of savings that emphasize savings for retirement as the dominant form of capital accumulation should give way to models that illuminate the determinants of intergenerational transfers

capital accumulation and uncertain lifetimes with adverse selection this paper examines the implications of adverse selection in the private annuity market for the pricing of private annuities and the consequent effects on constrption and bequest behavior with privately known heterogeneous mortality probabilities adverse selection causes the rate of return on private annuities to be less than the actuarially fair rate based on population average mortality however a fully funded social security system with compulsory participation can offer an implied rate of return equal to the actuarially fair rate based on population average mortality thus since social security offers a higher rate of return than private annuities consumers cannot completely offset the effects of social security by transacting in the private annuity market using an overlapping generations model with uncertain lifetimes we demonstrate that the introduction of actuarially fair social security reduces the steady state rate of return on annuities and raises the steady state levels of average bequests and average consumption of the young the steady state national capital stock rises or falls according to the strength of the bequest motive this abstract was borrowed from another version of this item

the policy anticipation hypothesis and the expected inflation hypothesis some new evidence using index linked bonds abstract using price index linked and conventional bonds issued by the uk government estimates of expected inflation and the expected real interest rate are derived these estimates are employed to investigate the relationship between components of the nominal interest rate and surprise monetary change the empirical results support the expected inflation hypothesis rather than the policy anticipation hypothesis

uncertain lifetimes and the welfare enhancing properties of annuity markets and social security this paper explores the implications of social security programs and annuity markets through which agents who are characterized by different distributions of length of lifetime share deathrelated risks when annuity markets operate a non discriminatory social security program affects only the intragenerational allocation of resources in the absence of private information regarding individual survival probabilities such a program will lead to a non optimal intragenerational allocation of resources however the presence of adverse selection considerations gives rise to a pareto improving role for a mandatory non discriminatory social security program

adverse selection in insurance markets policyholder evidence from the u k annuity market in this paper we investigate the importance of adverse selection in insurance markets we use a unique data set consisting of all annuity policies sold by a large u k insurance company since the early 1980s to analyze mortality differences among individuals who purchased different types of policies we find systematic relationships between ex post mortality and annuity policy characteristics such as whether the annuity will make payments to the estate in the event of an untimely death and whether the payments from the annuity rise over time these mortality patterns are consistent with the presence of asymmetric information in the annuity market we find no evidence of substantive mortality differences however across annuities of different size even though models of insurance market equilibrium with asymmetric information would predict such differences we also find that the pricing of various features of annuity contracts is consistent with the self selection patterns we find in mortality rates our results therefore suggest that selection may occur across many specific features of insurance contracts and that the absence of selection on one contract dimension does not preclude its presence on others this highlights the importance of considering the detailed features of insurance contracts when testing theoretical models of asymmetric information

should social security benefits be means tested social security retirement benefits distort the saving decisions of workers who are rational enough to save for their future since the implicit rate of return in an unfunded social security program is less than the marginal product of capital the resulting decline in saving causes a welfare loss the present paper examines the conditions under which the welfare loss could be reduced by replacing the current universal social security program with a means tested program that pays benefits only to those individuals with little or no other retirement income or assets every society must solve the problem of supporting those individuals who become too old to work but have not made adequate provision for their own old age by saving when they were young at the present time the major industrial countries of the world have responded to this problem by creating social security programs that tax the working population and use the proceeds to provide a universal benefit to all retirees regardless of their financial condition this universal provision of social security benefits distorts the saving decisions of those workers who are rational enough to plan for the future since the implicit rate of return that taxpayers get on their this research is part of the nber study of the government budget and the private economy a more complete version of this paper with some numerical calculations is available as nber working paper no 1775 feldstein 1985b i am grateful to gilbert metcalf for assistance with the calculations presented in this paper and for helpful discussions for a discussion of the effect of promised retirement benefits on the savings of employees see feldstein 1974 1982 barro 1974 1978 has discussed an interesting

adverse selection in the annuities market and the impact of privatizing social security the observation that few americans purchase life annuities has often been attributed to adverse selection a still unanswered question is whether observable price increases caused by adverse selection can be generated endogenously in a life cycle model this paper calibrates a pure life cycle model for a characteristic us cohort and reproduces three stylized facts adverse selection increases annuity prices by 7 10 percent the cost of adverse selection rises with the age of the annuitant and the cost is smaller for females than for males social security privatization could reduce annuity prices by between 2 and 3 percent

the effects of annuities bequests and aging in an overlapping generations model of endogenous growth we examine the effects of introducing actuarially fair annuity markets into an overlapping generations model of endogenous growth the complete annuitisation of agents wealth is not in general dynamically optimal the degree of annuitisation that is dynamically optimal depends nonmonotonically on the expected length of retirement and on the pay as you go social security tax rate the government has an incentive to restrict the availability of actuarially fair annuities contracts and can often move the economy from a pay as you go to a fully funded social security system via voluntary contributions to a government sponsored actuarially fair pension today accompanied by reductions in social security taxes tomorrow

economic news and equity market linkages between the u s and u k abstract the source of equity market linkages between the u s and u k is investigated by focusing on intraday price movements of stock index futures contracts we document heightened u k return volatility at 11 30 a m and 1 30 p m gmt which corresponds to regular macroeconomic releases in the u k and u s respectively the response of u k equities in the half hour surrounding the u s announcements is significant and similar to price movements for u s equities to the same announcements these results support the hypothesis that the documented international equity market linkages are attributable to reactions of foreign traders to public information originating from the u s

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

saving social security and uncertainty since alteration of the saving behavior of the present working generation may have such a significant impact on capital stock growth some concern has arisen about the effect of the social security system on saving behavior in response to this concern numerous empirical and theoretical analyses have been forthcoming most of the theoretical analyses either in the form of overlapping generations models 9 11 or simpler life cycle models 6 15 have indicated that unless specific parameter values utility functions and in some cases production functions are chosen the effect of a social security system on saving is indeterminate for example kurz 11 has shown that the introduction of a simple pay as you go social security system in an overlapping generations model in which individuals do not have a leisure choice will not have a predictable effect on the steady state level of the capital stock unless parameter values and the form of the production function are known similarly in life cycle models that include a leisure choice the effect of social security is difficult to determine although feldstein 6 shows that when the leisure choice is suppressed in such a model a social security system will have a negative impact on saving this indeterminacy has not been completely resolved by empirical work although the bulk of evidence 7 8 10 12 tends to support the view that social security has depressed saving in the past unfortunately with the exception of the work of sheshinski and weiss 16 little of the theoretical analysis deals with the effect on saving behavior of participants who are faced with uncertainty about future prices wages and social security benefits sheshinski and weiss have shown that in an overlapping generations model with uncertain lifetimes the effect of increasing the role of social security through balanced increases in benefits and contributions will actually lead to an increase in saving their analysis however does not include a leisure choice nor does it deal with other forms of uncertainty facing participants consequently we still lack more complete answers to the following basic questions will the introduction of a social security program in the presence of uncertainty

a note on the aggregate effects of social security abstract in an overlapping generations economy of karni and zilcha 1989 a fully funded social security program is shown to reduce the aggregate levels of output consumption employment and capital when the social security and the existing private annuities are equally unfair actuarially

uncertain health and survival effects on end of life consumption this article analyzes the impact of health and survival uncertainty on the saving and consumption decisions of retirees a dynamic programming approach is used to model the household s planning problem the utility parameters are estimated using panel data we find that a fall into poor health raises the marginal utility from consumption simulations are used to indicate the effects of falling into poor health and loss of spouse they reveal a large transfer from the healthy to the sick partner and a strong dependence of saving on the survivor benefits suggesting that concern about the surviving spouse is an important motive for saving

pay as you go or funded social security a general equilibrium comparison abstract this paper demonstrates that the analysis of fiscal sustainability of social security must include the education funding dimension of public policy which affects the productivity of future workers this fact is true under both social security regimes pay as you go payg and fully funded ff we consider an olg economy where the government in addition to running social security also funds education via a dedicated tax the education tax rates are chosen in each period by a majoritarian rule we demonstrate contrary to conjectures in the literature that the ff social security system produces political support for a relatively higher compared to payg education funding and hence generates higher rates of human capital accumulation physical capital accumulation and economic growth furthermore it also results in a comparatively lower degree of income inequality

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

aspirations habit formation and bequest motive we analyze how the presence of endogenous preferences affects the altruistic bequest motive from parents to children we will show that the existence of habits raises the threshold value of the intergenerational discount factor above which altruistic bequests are positive while aspiration formation could push this value down therefore the dynamic inefficiency of the economy with no altruism is not sufficient to prevent the bequest motive from being operative under aspiration formation we also discuss the implications of public debt when the bequest motive is inoperative and preferences exhibit habit and aspiration formation

full extraction of the surplus in bayesian and dominant strategy auctions we consider auctions for a single indivisible object in the case where the bidders have information about each other which is not available to the seller we show that the seller can use this information to his own benefit and we completely characterize the environ ments in which a well chosen auction gives him the same expected payoff as that obtainable were he able to sell the object with full information about each bidder s willingness to pay we provide this characterization for auctions in which the bidders have dominant strate gies and for those where the relevant equilibrium concept is bayesian nash in both set ups the existence of these auctions hinges on the possibility of constructing lotteries with the correct properties we consider the situation in which an agent the seller possesses one indivisible unit of a good to which he attaches no value but the good has value to a number of potential buyers and its transfer to one of them would increase social welfare in particular the transfer to the buyer with the highest valuation maximizes social welfare in this paper we completely characterize environments in which the seller can design an auction that will enable him to capture for himself the full increase in social welfare induced by the transfer of the good to the bidder with the highest willingness to pay if the seller had full information about the reservation prices of potential buyers his optimal selling strategy would be very simple he would announce a price equal or very close to the highest reservation value the optimal strategy for the bidder with the highest evaluation would be to accept the offer note that we are treating a situation in which the seller can commit himself to a price as a result of the exchange the utility of the seller increases by the full amount of the increase in social welfare and he has been able to fully extract the surplus in many circumstances however a seller has only imperfect knowledge of the buyers willingnesses to pay in this case he must find some mechanism or auction which will enable him to maximize his benefit from the sale of the object the auction literature starts with this observation and shows how the seller can by an astute choice of auction extract the largest possible fraction of the surplus in general the literature has shown that this proportion is strictly less than one in some circumstances the bidders will have information about each other which is not available to the seller for instance in auctions for petroleum drilling rights bidders know the results of geological tests which they have

precautionary saving in the small and in the large the theory of precautionary saving is shown to be isomorphic to the arrow pratt theory of risk aversion making possible the application of a large body of knowledge about risk aversion to precautionary saving and more generally to the theory of optimal choice under risk in particular a measure of the strength of the precautionary saving motive analogous to the arrow pratt measure of risk aversion is used to establish a number of new propositions about precautionary saving and to give a new interpretation of the dreze modigliani substitution effect copyright 1990 by the econometric society

uncertain inflation and social security indexation abstract this paper provides a theoretical analysis of the effects of the insurance feature of social security indexation on portfolio allocation and the stability of income and consumption of the retiree within the framework of a life cycle model of allocation under uncertainty the paper shows that the magnitudes of such effects depend on the importance of social security in total wealth the covariance of real portfolio returns with the inflation rate and more importantly whether there exists market failure in providing for inflation insurance