welfare economics risk and uncertainty social decisions in risky contexts raise a number of difficult questions such as 1 should social decisions be more or less risk averse than the average person 2 should we try to avoid large catastrophes more than frequent but limited harms with similar expected impact 3 should social decisions be ambiguity averse or stick to the expected utility canon this paper reviews the welfare economics of risk and uncertainty and examines possible answers to these questions based on the pros and cons of utilitarianism ex ante egalitarianism and ex post egalitarianism

the role of risk preferences in pay to bid auctions we analyze a new auction format in which bidders pay a fee each time they increase the auction price bidding fees are the primary source of revenue for the seller but produce the same expected revenue as standard auctions assuming risk neutral bidders if risk loving preferences are incorporated in the model expected revenue increases our model predicts a particular distribution of ending prices which we test against observed auction data the degree of fit depends on how unobserved parameters are chosen in particular a slight preference for risk has the biggest impact in explaining auction behavior suggesting that pay to bid auctions are a mild form of gambling this paper was accepted by peter wakker decision analysis

a note on environmental risk and the rate of discount abstract this paper examines the use of risk adjusted discount rates to evaluate future environmental risks it is determined that the risk adjusted discount rate should be lower not higher than the risk free rate if evaluation of future environmental risks is to point toward optimality

global risk investment and emotions we investigate a novel dynamic choice problem in an experiment where emotions are measured through self reports the choice problem concerns the investment of an amount of money in a safe option and a risky option when there is a global risk of losing all earnings from both options including any return from the risky option our key finding is that global risk can reduce the amount invested in the risky option this result cannot be explained by expected utility or by its main contenders rank dependent utility and cumulative prospect theory an explanation is offered by taking account of emotions using the emotion data from the experiment and recent psychological findings

expected utility skewness and the baseball betting market a subjective expected utility model is developed to explain the gambling behaviour of bettors on major league baseball games in the united states betting activity was examined over 15 seasons for the period 1978 1992 the observed overbetting of favourite teams by baseball bettors can be reconciled without abandoning the traditional assumption of risk aversion additionally there is some evidence to suggest that positive skewness has a discernible influence in the decision making process for higher odds contests

a rank dependent utility model of uncertain lifetime abstract in a continuous time life cycle model of consumption with an uncertain lifetime we use a non parametric specification of rank dependent utility theory to characterize the preferences of the agent we prove that time consistency holds for a subclass of probability weighting function providing the foundation for a constant rate of time preference that interacts multiplicatively with the hazard rate instead of additively as in the yaari 1965 seminal model we calibrate both models to explain the hump in the life cycle consumption and show that the multiplicative model is more robust

evaluating decision strategies for equity of public risks many important decisions include the loss of life among their possible consequences alternative actions have different implications for the number of possible fatalities the equity of those eventual fatalities and the equity of the process resulting in those fatalities this paper defines a concept of ex ante risk equity to address the equity of the process and distinguishes this concept from the ex post risk equity of the fatalities the paper indicates that an analysis of decision strategies addresses ex ante equity in this context both types of equity as well as loss of life are included in a von neumann morgenstern utility model developed to evaluate public risks this approach provides a method to investigate the implications of different value judgments in examining alternatives and illustrates an appropriate use of von neumann morgenstern utility for problems involving social consequences such as public risks

the ellsberg paradox and risk aversion an anticipated utility approach the paper describes a decision process under which it is rational to prefer a lottery with known probabilities to a similar ambiguous lottery where the decision maker does not know the exact values of the probabilities the ellsberg paradox this is done by modeling ambiguous lotteries as two stage lotteries by assuming the independence axiom without the reduction of compound lotteries axiom and by using the anticipated utility functional this paper also gives conditions under which less ambiguity is preferred and presents some comparative statics analysis as well as some inter personal comparisons finally it proves that within the anticipated utility framework risk and ambiguity are almost identical copyright 1987 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

the strategic implications of sunk costs a behavioral perspective abstract this paper examines some of the strategic implications of the sunk cost phenomenon in sequential allocation decisions drawing from psychology and behavioral decision theory we first present a taxonomy of possible causes for the sunk cost effect the tendency of many managers to throw good money after bad we then present the analysis of some implications of this behavior in strategic situations a two period strategic game is developed and analyzed to derive optimal allocations as a function of one player s sunk cost behavior we establish when this behavior can be used as a successful precommitment strategy by the sunk cost player and when it is exploitable by an opponent welfare implications are also explored the sunk cost effect constitutes a form of strategic preference manipulation in which a credible preference change can be induced to provide a strategic advantage to one of the players

optimism pessimism and financial bubbles this paper shows that it is possible to extend the scope of the existence of rational bubbles when uncertainty is introduced associated with rank dependent expected utility this rdu assumption can be viewed as a transformation of probabilities depending on the pessimism optimism of the agent the results show that pessimism favors the existence of deterministic bubbles when optimism may promote the existence of stochastic bubbles moreover under pessimism the rdu assumption may generate multiple bubbly equilibria the rdu assumption also leads to new conditions ensuring the absence of pareto optimality of the competitive equilibrium without bubbles these conditions still govern the existence of bubbles

social preferences under risk equality of opportunity versus equality of outcome this paper axiomatizes a utility function for social preferences under risk in the model a single parameter captures a preference for equality of opportunity i e equality of exante expected payoffs relative to equality of outcome i e equality of ex post payoffs in a deterministic environment the model reduces to the model of fehr and schmidt 1999 the model is consistent with recent experiments on probabilistic dictator games

generalized expected utility analysis of risk aversion with state dependent preferences in this paper the author develops measures of absolute risk aversion for preference relations on risky prospects that are state dependent and are representable by frechet differentiable nonlinear functionals a comparative statics analysis of optimal air travel insurance coverage illustrates the usefulness of the proposed measures it is also demonstrated that the analytical framework described above is consistent with the purchase of air travel insurance even in circumstances where expected utility theory is not copyright 1987 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

the effects of risk aversion on wagering point spread versus odds currently casinos and bookies use the point spread method for betting on football games since an odds system is used in various other sports what factors explain the current structure of the betting market as the bookie s profits are a percentage of the total money wagered the existence of point spread betting indicates that the total money wagered under this betting scheme is greater than that generated by odds betting this paper suggets that the current market structure is a consequence of risk averse attitudes of bettors

vickrey auctions in the theory of expected utility with rank dependent probabilities abstract when decision makers maximize expected utility with rank dependent probabilities and the object being auctioned is a risky prospect then with independent private value vickrey auctions lose their demand revealing property moreover they might be non pareto optimal

analysis of uncertainty as opposed to risk an experimental approach the paper illustrates the scope for enhancing the conceptual apparatus used by agricultural economists to analyse decision making under conditions of uncertainty selected empirical results from experiments on student subjects from three universities are reported three issues are considered first the reasons for choice and the understanding of a choice problem are examined second attitudes towards different levels of uncertainty are measured third the possibility that apparently non normative psychological factors influence choice is explored the paper serves to illustrate and support a number of methodological points the major points are that a risk uncertainty distinction is useful contrary to the aging conventional wisdom of economic theory that laboratory experiments can potentially provide data of use to agricultural economists and that predictive models of choice under uncertainty may be more accurate if they take account of psychological variables which influence the decision making processes of human subjects

failure of blackwell s theorem under machina s generalization of expected utility analysis without the independence axiom abstract considerable evidence suggests that the independence axiom of expected utility theory is not empirically supported in response machina has generalized expected utility theory in such a way that the independence axiom is not required most of the basic concepts and results of expected utility theory still hold under machina s generalization however blackwell s theorem a fundamental result in information economics fails to hold under machina s generalization of expected utility theory without the independence axiom

changing effects of monetary policy in the u s evidence from a time varying coefficient var we estimate a time varying coefficient var model for the us economy to analyse i if the effect of monetary policy on output has been changing systematically over time and ii if monetary policy has asymmetric effects over the business cycle we find that the impact of monetary policy shocks has been gradually declining over the sample period 1962 to 2002 as some theories of the monetary transmission mechanism imply in addition our results indicate that the effects of monetary policy are greater in a recession than in a boom

the rise of europe atlantic trade institutional change and economic growth the rise of western europe after 1500 is due largely to growth in countries with access to the atlantic ocean and with substantial trade with the new world africa and asia via the atlantic this trade and the associatedcolonialism affected europe not only directly but also indirectly by inducing institutional change where initial political institutions those established before 1500 placed significant checks on the monarchy the growth of atlantic trade strengthened merchant groups by constraining the power of the monarchy and helped merchants obtain changes in institutions to protect property rights these changes were central to subsequent economic growth

nonparametric test of the expected utility hypothesis a nonparametric test of the expected utility hypothesis is developed in this paper the expected utility hypothesis is shown to hold if there exists a feasible solution to a particular system of linear inequalities furthermore when a feasible solution exists boundaries on the coefficient of absolute risk aversion can be calculated explicitly the test is applied to data on land allocations modeled as choices over lottery sets results contrary to those obtained in many laboratory experiments show that in most cases the expected utility hypothesis cannot be rejected

bargaining and boldness abstract we study a multiperson bargaining problem with general risk preferences through the use of shaked s game of cycling offers with exogenous breakdown if preferences are smooth then as the risk of breakdown vanishes the limiting outcome is one in which bargainers are equally marginally bold where a bargainer s marginal boldness measures his willingness to risk disagreement in return for a marginal improvement in his position under smoothness any ordinal nash solution is an equally marginally bold outcome however unlike the concept of the ordinal nash solution a unique equally marginally bold outcome exists in natural cases in particular if all bargainers have risk averse preferences of the rank dependent expected utility type for these preferences the equally marginally bold outcome maximizes a bargaining power adjusted asymmetric nash product where the degree of asymmetry is determined by the disparity in the marginal valuation of certainty among bargainers journal of economic literature classification numbers c72 c78 d81

on the optimal design of lotteries is globally concave since thearguments against the plausibility of a convex utility function advanced in the previous sectionin relation to eu theory apply with equal force to the rdeu model by contrast as is shownbelow these arguments do not apply to risk seeking behavior associated with the possibility that

why people choose negative expected return assets an empirical examination of a utility theoretic explanation using a theoretical extension of the friedman and savage 1948 utility function developed in bhattacharyya 2003 we predict that for assets with negative expected returns such as state lottery games expected return will be a declining and convex function of skewness that is lottery players trade off expected return for skewness using two samples of lottery game data we find that our theoretical conclusions are supported by the empirical results the findings obtained here not only contribute to the literature on why individuals may participate in unfair gambles the framework could be extended to an analysis of the stock market where higher returns cannot be solely explained by risk variance

can expected utility theory explain gambling we investigate the ability of expected utility theory to account for simultaneous gambling and insurance contrary to a previous claim that borrowing and lending in perfect capital markets rules out a demand for gambles we show that expected utility theory with non concave utility functions can still explain gambling when the rates of interest and time preference are equal agents will seek to gamble unless income falls in a finite set of exceptional values when these rates differ there will be a range of incomes for which gambles are desired in both cases repeated gambling is not explained but market imperfections such as different borrowing and lending rates can account for persistent gambling provided the rates span the rate of time preference

solution and estimation of re macromodels with optimal policy macro models of monetary policy typically involve forward looking behavior except in rare circumstances we have to apply some numerical method to find the optimal policy and the rational expectations equilibrium this paper summarizes a few useful methods and shows how they can be combined with a kalman filter to estimate the deep model parameters with maximum likelihood simulations of a macro model with staggered price setting interest rate elastic output and optimal monetary policy illustrate the properties of this estimation approach

social context and the utility of wealth addressing the markowitz challenge abstract paradoxically there is a demand for both risk and insurance markowitz markowitz h 1952 the utility of wealth journal of political economy 60 151 158 laid the foundation for an explanation to this paradox markowitz challenged future researchers to build upon his foundation an operational specification of the taste for wealth this paper addresses the markowitz challenge by building social context variables into his model of individual utility verifiable implications about gambling insuring and peer selection are derived from the augmented markowitz utility function

changing time attitudes in intertemporal analysis intertemporal analysis is extended by generalizing the time weight function of an investor s utility function to account for changes in time attitudes the resulting measures of decreasing constant and increasing time attitudes are comparable to the arrow pratt measures of risk attitudes they help to enrich intertemporal theory provide meaningful hypotheses for testing and broaden the scope for decision analysis over time effects of the time attitude measures are illustrated in a model of an agricultural firm

decision making over time and under uncertainty a common approach this paper considers a number of parallels between risky and intertemporal choice we begin by demonstrating a one to one correspondence between the behavioral violations of the respective normative theories for the two domains i e expected utility and discounted utility models we argue that such violations or preference reversals are broadly consistent with three propositions about the weight that an attribute receives in both types of multiattribute choice specifically it appears that 1 if we add a constant to all values of an attribute then that attribute becomes less important 2 if we proportionately increase all values of an attribute or if we change the sign of an attribute from positive to negative then that attribute becomes more important the generality of these propositions as well as the constraints they would impose on separable representations of multiattribute preferences is discussed

a theory of rational addiction we develop a theory of rational addiction in which rationality means a consistent plan to maximize utility over time strong addiction to a good requires a big effect of past consumption of the good on current consumption such powerful complementarities cause some steady states to be unstable they are an important part of our analysis because even small deviations from the consumption at an unstable steady state can lead to large cumulative rises over time in addictive consumption or to rapid falls in consumption to abstention our theory also implies that cold turkey is used to end strong addictions that addicts often go on binges that addicts respond more to permanent than to temporary changes in prices of addictive goods and that anxiety and tensions can precipitate an addiction

many good choice axioms when can many good lotteries be treated as money lotteries abstract without the independence axiom a weaker substitution axiom adi is necessary for the preferences over money lotteries induced by the money metric utility function to be well behaved given adi the agent s preferences over many good lotteries can be reconstructed from knowledge of preferences over money lotteries and over sure multivariate outcomes moreover other substitution properties of underlying many good lottery preferences are inherited by the money lottery preferences we analyze the formal and intuitive nature of adi and conclude that analysis of choice under uncertainty without adi cannot be one dimensional

changing tastes and effective consistency in a single commodity setting with changing tastes an individual s consumption plan can be obtained using naive or sophisticated choice we provide two sufficient conditions for when the solutions are unique and agree and the common plan is representable by a non changing tastes utility because the solution is not revised over time the plan and associated preferences are referred to as being effectively consistent afriat style revealed preference tests are derived the assumption of effective consistency can mitigate the problems of vulnerability to dutch books non existence of a competitive equilibrium and the aggregation of heterogeneous agents with changing tastes abstract from author

welfare maximization entices participation abstract we consider randomized public good mechanisms with optional participation preferences over lotteries are modeled using skew symmetric bilinear ssb utility functions a generalization of classic von neumann morgenstern utility functions we show that every welfare maximizing mechanism entices participation and that the converse holds under additional assumptions as a corollary we obtain a characterization of an attractive randomized voting rule that satisfies condorcet consistency and entices participation this stands in contrast to moulin s well known no show paradox j of econ theory 45 53 64 1988 which shows that no deterministic voting rule can satisfy both properties simultaneously

making book against oneself the independence axiom and nonlinear utility theory an individual with known preferences over lotteries can be led to accept random wealth distributions different from his initial endowment by a sequential process in which some uncertainty is resolved and he is offered a new lottery in place of the remaining uncertainty this paper examines the restrictions that can be placed on an individual s preferences by axioms that stipulate that such a process not be able to generate a new wealth distribution that is prima facie inferior to the original the relationship of these axioms to the independence axiom of von neumann and morgenstern and to the quasi convexity of preferences in the wealth distribution are explored

the demarcation of land and the role of coordinating property institutions we use a natural experiment in nineteenth century ohio to analyze the economic effects of two dominant land demarcation regimes metes and bounds mb and the rectangular system rs mb is decentralized with plot shapes alignment and sizes defined individually rs is a centralized grid of uniform square plots that does not vary with topography we find large initial net benefits in land values from the rs and also that these effects persist into the twenty first century these findings reveal the importance of transaction costs and networks in affecting property rights land values markets and economic growth

cumulative prospect theory option returns and the variance premium the variance premium and the pricing of out of the money otm equity index options are major challenges to standard asset pricing models we develop a tractable equilibrium model with cumulative prospect theory cpt preferences that can overcome both challenges the key insight is that the variance premium can be written as the expected return on a portfolio of otm call and put options and the probability weighting feature of cpt can explain the puzzlingly low returns observed for these options using gmm on a sample of u s index option returns between 1996 and 2010 we show that the cpt model ts well observed option prices and therefore the variance premium in a dynamic setting probability weighting and time varying equity return volatility combine to match the observed time series pattern of the variance premium

disappointment and dynamic consistency in choice under uncertainty the central proposition of disappointment theory is that an individual forms expectations about uncertain prospects and that if the actual consequence turns out to be worse than or better than that expectation the individual experiences a sensation of disappointment or elation generating a decrement or increment of utility which modifies the basic utility derived from the consequence by incorporating a simple disappointment elation function into a model of individual choice many observed violations of conventional expected utility axioms including violations of savage s sure thing principle and the isolation effect can be predicted and defended as rational and dynamically consistent behaviour

large scale institutional changes land demarcation in the british empire abstract we examine adoption of land demarcation in the british empire during the seventeenth through nineteenth centuries we develop a model and test its implications against data from temperate british colonies in north america australia and new zealand three arrangements were implemented individualized idiosyncratic metes and bounds a centralized uniform rectangular system and a centralized nonuniform demarcation system the choice of arrangement is determined using demarcation topographical and soil quality data sets with qualitative historical information we find that centralized systems provide coordination benefits but adoption is less likely when implementation is slow and controlling settlement is costly in centralized systems we find that uniform rectangular demarcation lowers transaction costs but its rigid structure is costly in rugged terrain and alternatives are adopted

risk preference and the work leisure trade off the paper investigates the interrelationships between the wage rate period of employment work leisure choice and the attitude toward risk the model makes risk preference endogenous given external forces acting on individual choice beginning with assumptions normally considered consistent with risk aversion namely concave utility with respect to leisure and wealth along with perfect markets rational behavior consistent with the insurance buying gambler is shown to be a reasonable possibility the theory also provides an explanation for the repeating gambler paradox

syndication institutionalization and lottery play1 why do people play the lottery since lottery tickets are assets with negative expected return lottery play challenges the basic assumptions of economic theory this article approaches lottery play from a networks perspective and focuses on syndicate play a comparison of the development of lottery markets in germany austria spain and portugal from the 17th century onward shows that lottery play declined with rising incomes except in countries in which syndicate play diffused widely namely spain and to a lesser extent portugal although syndicating originated among the relatively poor as a response to an increase in lottery prices it persisted even when individual play became affordable this article contends that syndicating endured because of an institutionalization process by which lottery tickets have transformed from purely economic assets into symbolic carriers of interpersonal ties that convey membership and status position in relevant social networks

gambles and the shadow price of death recent papers on the value of life involve preferences of the sort introduced by milton friedman and leonard savage 1948 1 given the choice between undergoing a particular gamble in wealth and possessing the mathematical expectation of the payoffs of the gamble the consumers in these studies may prefer the gamble the presence of such risk loving preferences is inferred from two well established facts life is an indivisible commodity in the models and indivisibility leads to preference for gambles the former fact is made clear by philip cook and daniel graham the latter was first noted by yew kwang ng 1965 and is widely known in spite of the obvious connection the implications of risk loving tastes in this area have not been explored this paper examines some implications of such risk loving the idea that indivisibility produces friedman savage preferences and that such preferences create a demand for gambles is extended in section i to a theory of demand for indivisible goods and derived demand for associated optimum gambles this theory suggests that the price of an indivisible good will not compensate for possessing or not possessing the good section ii applies the demand theory to an equilibrium model of labor supply that is relevant to the determination of the value of life in this model the wage diflerential is useful in guiding policy toward public risks in spite of the fact that the differential is not compensating i demand for gambles and demand for goods

new keynesian economics and the phillips curve models with sticky prices are an important part of new keynesian economics the author shows that several of the new keynesian models imply a formulation that is similar to the expectations augmented phillips curve of milton friedman and edmund phelps he then presents new estimates of the new keynesian phillips curve the author uses two proxies for price expectations survey based measures and an econometric based measure originally developed by bennett mccallum 1976 overall the results are consistent with the model but the survey based results are more precise suggesting that the surveys may be better measures of actual expectations copyright 1995 by ohio state university press

equilibrium without independence abstract because players whose preferences violate the von neumann morgenstern independence axiom may be unwilling to randomize as mixed strategy nash equilibrium would require a nash equilibrium may not exist without independence this paper generalizes nash s definition of equilibrium retaining its rational expectations spirit but relaxing its requirement that a player must bear as much uncertainty about his own strategy choice as other players do the resulting notion equilibrium in beliefs is equivalent to nash equilibrium when independence is satisfied but exists without independence this makes it possible to study the robustness of equilibrium comparative statics results to violations of independence

prospect theory in a dynamic game theory and evidence from online pay per bid auctions abundant evidence exists that expected utility theory does not adequately describe decision making under risk although prospect theory is a popular alternative it is rarely applied in strategic situations in which risk arises through individual interactions this study fills this research gap by incorporating prospect theory preferences into a dynamic game theoretic model using a large field data set from multiple online pay per bid auction sites the authors empirically show that their proposed model with prospect theory preferences makes a better out of sample prediction than a corresponding expected utility model prospect theory also provides a unified explanation for two behavioral anomalies average auctioneer revenues above current retail prices and the sunk cost fallacy the empirical results indicate that bidders are loss averse and overweight small probabilities such that the expected revenue of the auction exceeds the current retail price by 25 46 the authors illustrate and empirically confirm a managerial implication for how an auctioneer can increase revenue by changing the details of the auction design

monetary policy trade offs and the correlation between nominal interest rates and real output the authors present a structural model of the u s economy that combines their price contracting specification with a term structure relationship an aggregate demand curve and a monetary policy reaction function the model matches important features of postwar data well and provides a structural explanation of the correlation between real output and the short term nominal rate of interest the authors perform a battery of monetary policy experiments that show that as viewed through the lens of this model monetary policy has struck a good balance recently among competing monetary policy objectives copyright 1995 by american economic association

what if the fed had been an inflation nutter a structural rational expectations model of us monetary policy is used to make a counterfactual experiment of a strongly inflation averse federal reserve bank results for us interest rates output and inflation over 1965 1999 are discussed

trade expansion and contract enforcement consider a world of traders separated in geographic economic or social space honest trade offers larger gains for more distant traders but frequencies of meetings and information flows about cheating have local bias honesty is self enforcing only between pairs of sufficiently close neighbors global honesty prevails only in a sufficiently small world the extent of self enforcing honesty is likely to decrease when the world expands beyond this size costly external enforcement is useful only if the world is sufficiently large and its net payoff need not be larger than that of a self governing small community intermediate size worlds fare worst

food scares in an uncertain world we develop a model that explains the stylized facts of food scares an immediate and sharp decline in consumption of the product followed by a slow and frequently partial recovery of demand after the scare passes the model is used in conjunction with the natural experiment afforded by the mad cow crisis to elicit empirical information on decision makers perception of uncertainty our theoretical and quantitative results suggest that observed behavior is consistent with sharp changes in beliefs and the presence of knightian uncertainty as measured by the degree of imprecision in our model

risk aversion in the theory of expected utility with rank dependent probabilities expected utility with rank dependent probability theory is a model of decision making under risk where the preference relations on the set of probability distributions is represented by the mathematical expectation of a utility function with respect to a transformation of the probability distributions on the set of outcomes this paper defines based on g teaux differentiability measures of risk aversion for such preferences which characterize the relation more risk averse and applies these measures to the analysis of unconditional and conditional portfolio choice problems

do non expected utility choice patterns spring from hazy preferences an experimental study of choice errors individuals often have only incompletely known preferences when choosing between pair wise gambles particular presentations of the choice problem may then passively encourage the use of some choice method to clarify the preference different presentational displays can then lead to choice patterns predicted by one or other generalised expected utility theory when a preference is not or cannot be constructed choices will be arbitrary i run an experiment that uses three different presentational displays and incorporates a strength of preference indicator the experiment investigates regret theory as an example of a generalised expected utility theory as preference strength is found to vary by display regret effects event splitting effects and choice reversals are all found to be display dependent it is suggested that the evidence is best explained by assuming incomplete eu preferences which are clarified by constructive heuristics rather than some generalised expected utility model coupled with an error term

an intertemporal analysis of the interdependence between risk preference retirement and work rate decisions indivisibilities in consumption investment choice of employment and so forth have been used by others to justify the behavior of the insurance buying gambler unfortunately these theories ignore the market incentives to make the indivisible divisible through leasing or variation in quality as well as individual initiative through borrowing and lending in this paper the same behavior toward risk is explained without resort to indivisibilities or market imperfections using the effect of work rates and retirement decisions on lifetime earning profiles this is done using assumptions normally consistent with risk aversion diminishing marginal utility of consumption and time separable utility

theories of risk testing investor behaviour on the taiwan stock and stock index futures markets investor behavior towards risk lies at the heart of economic decision making in general and modern investment theory and practice in particular this paper uses both the mean variance mv criterion and stochastic dominance sd procedures to analyze the preferences for four of the most widely studied investor types in the taiwan stock and stock index futures market we find that risk averters concave utility function prefer spot to futures whereas risk seekers convex utility function prefer futures to spot our findings also show that investors with s shaped utility functions prefer spot futures to futures spot when markets move upward downward finally our results imply that investors with reverse s shaped utility functions prefer futures spot to spot futures when markets move upward downward these results are robust with respect to sub periods spot returns including dividends and diversification although we do not check whether risk averters risk seekers and investors with s shaped and reverse sshaped utility functions actually exist in the market we do show that their existence is plausible the implications of our findings on market efficiency and the existence of arbitrage opportunities are also discussed in this study

savings and prize linked savings accounts abstract many households have insufficient savings to handle moderate and routine consumption shocks many of these financially fragile households also have the highest lottery expenditures as a proportion of income this combination suggests that prize linked savings pls accounts combining security of principal with lottery type jackpots can increase savings among these at risk households results from an online experiment show that the introduction of pls accounts increase total savings and reduce lottery expenditures significantly especially among individuals with the lowest levels of savings and income the results imply that pls accounts offer a plausible market based solution to encourage individuals to increase savings

decision theory under ambiguity we review recent advances in the field of decision making under uncertainty or ambiguity we start with a presentation of the general approach to a decision problem under uncertainty as well as the standard bayesian treatment and issues with this treatment we present more general approaches choquet expected utility maximin expected utility smooth ambiguity and so forth that have been developed in the literature under the name of models of ambiguity sensitive preferences we draw a distinction between fully subjective models and models incorporating explicitly some information we review definitions and characterizations of ambiguity aversion in these models we mention the challenges posed by some of the models presented we end with a review of part of the experimental literature and applications of these models to economic settings

the marginal utility of income does not increase borrowing lending and friedman savage gambles there has been a great deal of discussion about whether the marginal utility of income rises with income most notably milton friedman and leonard j savage argued in their classic paper that the willingness to gamble implies that the marginal utility of income is rising over a range the discussions of rising marginal utility and of friedman savage gambles have proceeded independently of the literature on time preference although the issues are in fact related logically drawing on this logical relationship we shall show 1 that at least when intertemporal utility is separable the stable levels of consumption that are usually observed imply that the marginal utility of income decreases as income rises 2 even if the marginal utility of income does increase friedman savage gambles normally will not maximize utility saving and dissaving can attain the levels of consumption which generate the most utility per dollar of income at a lower cost than gambles unless imperfections in the capital market are severe 3 even when the utility function is not temporally separable repeated gambling cannot be a rational way of dealing with a rising marginal utility of income we therefore conclude that observed gambling is seldom if ever explained by the logic set out in friedman and savage s seminal paper in view particularly of the stability of consumption levels and the lack of friedmansavage gambles we conclude that marginal utility of income does not rise with income i a conceptual framework

market efficiency and the favorite longshot bias the baseball betting market this paper examines the efficiency of the legal gambling market for major league baseball weak form tests of market efficiency within and across odds lines are performed surprisingly the consistently observed favorite longshot bias in racetrack betting is shown to exist in reverse for baseball bettors however these and other deviations from efficiency are shown to be insufficient to allow for profitable betting strategies when commissions are considered

testing risklove in an experimental racetrack abstract this paper tests the asch quandt betting hypothesis which accounts for the ubiquitous underbetting overbetting favourite longshot phenomenon found at most racetracks by postulating that horserace wagering is a consumption activity an experimental racetrack was designed with only off track betting permissible thereby eliminating much or all of the consumption involved but the basic anomaly remained and in a somewhat stronger form it is hypothesized that the observed betting behaviour of our subjects is consistent with prospect theory and its two outcome equivalent rank dependent expected utility theory

a model of casino gambling we show that prospect theory offers a rich theory of casino gambling one that captures several features of actual gambling behavior first we demonstrate that for a wide range of preference parameter values a prospect theory agent would be willing to gamble in a casino even if the casino offers only bets with no skewness and with zero or negative expected value second we show that the probability weighting embedded in prospect theory leads to a plausible time inconsistency at the moment he enters a casino the agent plans to follow one particular gambling strategy but after he starts playing he wants to switch to a different strategy the model therefore predicts heterogeneity in gambling behavior how a gambler behaves depends on whether he is aware of the time inconsistency and if he is aware of it on whether he can commit in advance to his initial plan of action this paper was accepted by brad barber teck ho and terrance odean special issue editors

the integration of claims to health care a programming approach the paper contributes to the use of social choice and welfare theory in health economics by developing and applying the integration of claims framework to health care rationing related to sen s critique of neo classical welfare economics the integration of claims framework recognises three primitive sources of claim consequences deontology and procedures a taxonomy is presented with the aid of which it is shown that social welfare functions reflecting these claims individually or together can be specified some of the resulting social choice rules can be regarded as generalisations of health maximisation and all have normative justifications though the justifications may not be universally acceptable the paper shows how non linear programming can be used to operationalise such choice rules and illustrates their differential impacts on the optimal provision of health care following discussion of relations to the capabilities framework and the context in which rationing occurs the paper concludes that the integration of claims provides a viable framework for modelling health care rationing that is technically rigorous general and tractable as well as being consistent with relevant moral considerations and citizen preferences

intrinsic preference for information abstract suppose agents value information not only to make contingent plans but also intrinsically how are such attitudes toward information related to attitudes toward risk we generalize the kreps porteus recursive expected utility model dropping both recursivity and expected utility there is a geometric analogy between risk and information we characterize intrinsic information loving in general by a substitution property analogous to multivariate risk loving and for smooth preferences by the convexity of gateaux derivatives even with recursivity preference for information does not imply expected utility we provide an example we examine connections between information loving and risk aversion for early and late resolving risks journal of economic literatureclassification numbers d80 d81

risk preferences are not time preferences risk and time are intertwined the present is known while the future is inherently risky this is problematic when studying time prefer ences since uncontrolled risk can generate apparently present biased behavior we systematically manipulate risk in an intertemporal choice experiment discounted expected utility performs well with risk but when certainty is added common ratio predictions fail sharply the data cannot be explained by prospect theory hyperbolic discounting or preferences for resolution of uncertainty but seem consistent with a direct preference for certainty the data suggest strongly a difference between risk and time preferences jel c91 d81 d91 understanding individual decision making under risk and over time are two foundations of economic analysis 1 in both areas there has been research to suggest that standard models of expected utility eu and exponential discounting are flawed or incomplete regarding time experimental research has uncovered evidence of a present bias or hyperbolic discounting frederick loewenstein and o donoghue 2002 regarding risk there are number of well documented departures from eu such as the allais 1953 common consequence and common ratio paradoxes an organizing principle behind expected utility violations is that they seem to arise as so called boundary effects where certainty and uncertainty are combined camerer 1992 harless and camerer 1994 and starmer 2000 indicate that violations of expected utility are notably less prevalent when all choices are uncertain this observation is especially interesting when considering decisions about risk taking over time in particular certainty and uncertainty are combined in intertemporal decisions the present is known and certain while the future is inherently risky this observation is problematic if one intends to study time preference in isolation from

contingent portfolio programming for the management of risky projects methods for selecting a research and development r d project portfolio have attracted considerable interest among practitioners and academics this notwithstanding the industrial uptake of these methods has remained limited partly because of the difficulties of capturing relevant concerns in r d portfolio management motivated by these difficulties we develop contingent portfolio programming cpp which extends earlier approaches in that it i uses states of nature to capture exogenous uncertainties ii models resources through dynamic state variables and iii provides guidance for the selection of an optimal project portfolio that is compatible with the decision maker s risk attitude although cpp is presented here in the context of r d project portfolios it is applicable to a variety of investment problems where the dynamics and interactions of investment opportunities must be accounted for

lottery markets design micro structure and macro behavior an ace approach abstract an agent based computational modeling of the lottery market is established in this paper to study the design issue in terms of the lottery tax rate as well as the emerging market behavior by using genetic algorithms and fuzzy logic lottery participants are modeled as autonomous agents who may endogenously adapt to exhibit behavioral properties consistent with well noticed behavior of lottery markets three major findings are presented first as anticipated a laffer curve is found in this model nonetheless the laffer curve has a flat top which indicates the non uniqueness of the optimal lottery tax rate second conscious selection behavior is also observed but it becomes weaker as time goes on third for the halo effect we observe exactly the opposite each of these three findings are then compared with available empirical results and the mechanism of genetic algorithms is further examined in light of the anti halo effect

costly predation and the distribution of competence an evolutionary game model shows how an equilibrium distribution of competence may evolve when members of a population prey on one another but when predatory competence is costly to acquire under one interpretation the competence distribution is an endogenously determined distribution of bounded rationality an example shows how tricksters and suckers might coexist in the long run the analysis leads to a curious result about a mixed equilibrium for a symmetric zero sum game an increase in the costs of one or more competence levels has exactly zero effect on the fraction of the population at those levels