information transmission cournot and bertrand equilibria we examine how incentives for two duopolists to honestly share information change depending upon the nature of competition cournot or bertrand and the nature of the information structure while in earlier papers uncertainty is about an unknown common demand intercept in the present paper uncertainty is about unknown private costs the different information structure reverses the incentives to share information while with unknown common demand sharing is a dominant strategy with bertrand competition and concealing is a dominant strategy with cournot competition with unknown private costs sharing is a dominant strategy with cournot competition and concealing is a dominant strategy with bertrand competition

global warming irreversibility and learning a number of economists have argued that the literature on the irreversibility effect implies that current abatement of greenhouse gas emissions should be greater when there is the possibility of obtaining better information in the future about the potential damages from global warming than when there is no possibility of obtaining better information in this paper we show that even the simplest model of global warming does not satisfy either of epstein s 1980 sufficient conditions so it is not possible to use epstein s analysis to tell whether the irreversibility effect applies to models of global warming we derive an alternative sufficient condition for the irreversibility effect to hold

the role of uncertainty and learning for the success of international climate agreements abstract transnational externalities e g transboundary pollution trade contagious diseases and terrorism warrant coordination and cooperation between governments but this proves often difficult one reason for the meager success is the public good character of many of these economic problems encouraging free riding another reason one might suspect is uncertainty surrounding most environmental problems and in particular climate change this provides often an excuse for remaining inactive paradoxically some recent papers have concluded just the opposite the veil of uncertainty can be conducive to the success of international environmental cooperation in this paper we explain why and under which conditions this can be true however we argue that those conditions are the exception rather than the rule most important we suggest a mechanism for those conditions where learning has a negative effect on the success of cooperation which removes this effect or even turns it into a positive effect our results apply beyond the specifics of climate change to similar problems where cooperation generates positive externalities

the disposition effect in farmers selling behavior an experimental investigation the identification of the optimal selling time of stored goods is among the most essential economic decisions on a farm beyond monetary aspects behavioral factors influence farmers selling decisions in financial economics the disposition effect is a commonly observed phenomenon it describes the fact that investors hold losing stocks too long while they sell stocks that gained in value too early in the context of agriculture this behavioral bias has not been analyzed thoroughly yet to close this research gap we conducted an incentivized online experiment with 112 farmers from germany the experimental design was based on a well proven experiment from financial economics and adapted to an agricultural decision context where stored goods must be sold farmers were provided information on the uncertain price developments in addition lotteries were conducted to elicit farmers risk attitude probability weighting and loss aversion results indicate that there is a robust disposition effect in farmers selling behavior furthermore more loss averse farmers exhibited a higher realization of gains

a closed form solution for a model of precautionary saving this paper analyses life cycle consumption plans and distinguishes between temporal risk aversion and intertemporal substitution the results assume that felicity functions are quadratic and that income follows a linear model with normally distributed errors stochastic dynamic programming then yields closed loop linear decision rules certainty equivalence no longer holds but instead households play a min max strategy against nature one finds a rationale for precautionary saving and a larger sensitivity of changes in consumption to income innovations

uncertainty learning and international environmental policy coordination in this paper we construct a simple model of global warming which captures a number of key features of the global warming problem i environmental damages are related to the stock of greenhouse gases in the atmosphere ii the global commons nature of the problem means that these are strategic interactions between the emissions policies of the governments of individual nation states iii there is uncertainty about the extent of the future damages that will be incurred by each country from any given level of concentration of greenhouse gases but there is the possibility that at a future date better information about the true extent of environmental damages may become available an important aspect of the problem is the extent to which damages in different countries may be correlated in the first part of the paper we consider a simple model with two symmetric countries and show that the value of perfect information is an increasing function of the correlation between damages in the two countries in both the cooperative and non cooperative equilibria however while the value of perfect information is always non negative in the cooperative equilibrium in the non cooperative equilibrium there is a critical value of the correlation coefficient below which the value of perfect information will be negative in the second part of the paper we construct an empirical model of global warming distinguishing between oecd and non oecd countries and show that in the non cooperative equilibrium the value of perfect information for oecd countries is negative when the correlation coefficient between environmental damages for oecd and non oecd countries is negative the implications of these results for international agreements are discussed

fundamental irreversibilities in stock externalities abstract this paper concerns the irreversibility effect in stock externalities in an environment of uncertainty with learning taking place one may wish to under emit today to avoid potential environmental irreversibilities alternatively one may wish to under invest in pollution control capital avoiding investments in sunk capital that turn out to be wasted the paper develops theoretical results on the tension between these two effects and separates risk aversion from the irreversibility effect the paper also presents a simple example in climate change policy

a cost benefit analysis of slowing climate change there are many conflicting views regarding the true dimensions of the climate change problem often these viewpoints are based on different estimates of key parameters with little indication as to why parameter estimates vary so much and which ones might be the more reliable the prospects for a co ordinated strategy to tackle climate change appear dim little consensus has emerged for example regarding the costs of abating carbon emissions some take the view that considerable improvements in energy efficiency are available at negative cost by setting minimum efficiency standards for vehicles and domestic appliances e g mills et al 1991 others regard the macroeconomic costs of even small reductions in carbon emissions as substantial manne and richels 1993 in the judgement of other researchers a proportion of carbon emissions arise purely as a result of institutional failings either at a regional level in the subsidies paid to fossil fuel energy producers in the erroneous belief that this promotes economic growth shah and larsen 1994 in failure to deal with air pollution glomsrod et al 1992 and vehicle congestion in urban areas hughes 1994 or at a global level in failing to make appropriate transfers to those countries whose forests contain rich biodiversity which we would wish to preserve pearce 1991

technological change occupational tasks and declining immigrant outcomes implications for earnings and income inequality in canada the earnings and occupational task requirements of immigrants to canada are analyzed the growing education levels of immigrants in the 1990s have not led to a large improvement in earnings as one might expect if growing computerization and the resulting technological change was leading to a rising return to non routine cognitive skills and a greater wage return to university education controlling for education we find a pronounced cross arrival cohort decline in earnings that coincided with cross cohort declines in cognitive occupational task requirements and cross cohort increases in manual occupational task requirements the immigrant earnings outcomes had only a small effect on overall canadian earnings inequality resume changement technique t ches occupationnelles et resultats declinants pour les immigrants implications pour l inegalite des gains et des revenus au canada les auteurs analysent les gains et les prerequis des t ches occupationnelles des immigrants les niveaux d education croissants des immigrants dans les annees 1990 n ont pas entraine une grande amelioration dans les gains comme on aurait pu s y attendre si l informatisation accrue et les changements techniques qui s ensuivent ont entraine un rendement croissant sur des habiletes cognitives non routinieres et un rendement salarial plus grand sur l education universitaire normalisant pour le niveau d education on decouvre un declin entre cohortes dans les gains qui coincide avec un declin dans ce que reclament les t ches en termes d habiletes cognitives et un accroissement de ce que reclament les occupations manuelles l effet de ces changements sur les gains des immigrants n a eu qu un faible impact sur l inegalite des gains au canada

prospect theory and risk preferences of oregon seed producers prospect theory relates risk preference classifications to gains and losses from a reference income level this study applies prospect theory to reinterpret historical studies of risk preferences of oregon grass seed growers a significant relationship between changes in classifications of preferences and changes in income was found results indicated that those who lost income were concentrated in the category of changing to risk preferrers income changes calculated from crop combinations were also found to be correlated in a theoretically correct pattern with positive measures of risk from crop enterprises the research therefore is consistent with further applications of prospect theory to farm management

providing global public goods under uncertainty abstract we study how uncertainty and risk aversion affect international agreements to supply global public goods we consider a benchmark model with homogeneous countries and linear payoffs when countries directly contribute to a public good uncertainty tends to lower signatories efforts but may increase participation despite risk aversion uncertainty may improve welfare in contrast when countries try to reduce a global public bad uncertainty tends to increase signatories efforts and decrease participation in that case an ex ante reduction of uncertainty may have a large positive multiplier effect on welfare

saving and liquidity constraints this paper is concerned with the theory of saving when consumers are not permitted to borrow and with the ability of such a theory to account for some of the stylized facts of saving behavior the models presented in the paper seem to account for important aspects of reality that are not explained by traditional life cycle models copyright 1991 by the econometric society

a dynamic game of emissions pollution with uncertainty and learning we introduce learning in a dynamic game of international pollution with ecological uncertainty we characterize and compare the feedback non cooperative emissions strategies of players when the players do not know the distribution of ecological uncertainty but they gain information learn about it we then compare our learning model with the benchmark model of full information where players know the distribution of ecological uncertainty we find that uncertainty due to anticipative learning induces a decrease in total emissions but not necessarily in individual emissions further the effect of structural uncertainty on total and individual emissions depends on the beliefs distribution and bias moreover we obtain that if a player s beliefs change toward more optimistic views or if she feels that the situation is less risky then she increases her emissions while others react to this change and decrease their emissions

research frontiers in the economics of climate change academic and policy debates over climate change risks and policies have stimulated economic research in a variety of fields in this article i briefly discuss eight overlapping areas of current research in which further effort is particularly warranted these areas include decision criteria for policy risk assessment and adaptation uncertainty and learning abatement cost and the innovation and diffusion of technology and the credibility of policies and international agreements further analysis in these areas not only will advance academic understanding but also will provide insights of considerable importance to policymakers

a household level study of the determinants of incomes and consumption this paper uses micro data to estimate the determinants of household income and to measure how human capital and earnings uncertainty affect consumption we also estimate how home owners react to capital gains on housing and assess whether these gains are treated in the same way as other sources of income using uk micro data we show that estimates of permanent income and of earnings uncertainty have powerful effects on spending we find that precautionary motives may account for a substantial proportion of household saving we also provide estimates of the shape of the earnings profile for various occupational groups and of the returns to education in different professions copyright 1997 by royal economic society

producer attitudes toward output price risk experimental evidence from the lab and from the field a number of agricultural and food policy instruments are predicated on the idea that producers dislike output price risk we test experimentally some theoretical predictions about the behavior of producers in the face of output price risk namely sandmo s 1971 prediction that price risk at the extensive margin causes risk averse producers to decrease how much they produce and batra and ullah s 1974 prediction that price risk at the intensive margin causes producers whose preferences exhibit decreasing absolute risk aversion to further decrease how much they produce we do so in labs with us college students as well as in the field with peruvian farmers first as regards price risk at the extensive margin we find no support for sandmo s prediction second consistent with batra and ullah s prediction we find that output decreases in response to price risk at the intensive margin when imposing a linear relationship between output and price risk when relaxing the assumption of linearity between output and price risk however we find a nonmonotonic relationship between output and price risk taken together these results are broadly inconsistent with expected utility theory alternative models of behavior in the face of risk such as prospect theory may explain the behavior we observe

close encounters of two kinds false alarms and dashed hopes people are frequently exposed to potentially attractive events that are subsequently and unexpectedly reversed and to potentially painful events which are also unexpectedly reversed in the process of being returned to the initial asset position does the sequence in which the positive and negative events occur matter this issue of the combined effect of pleasurable and painful stimuli has received scant theoretical or empirical attention we attempt to fill this lacuna in the literature by studying the retrospective evaluation of surprises that return individuals to their original economic state although such surprises do not change an individual s original economic state we argue that the individual s psychological state changes and the final affective state is among other things a function of the sequence in which the events occur from a theoretical standpoint several perspectives can be brought to bear on the issue for instance one reading of mental accounting based on prospect theory s value function would predict that losses should dominate gains and therefore regardless of sequence people should be unhappy when exposed to two economically equivalent outcomes of different signs conversely the literature on intertemporal choice would suggest that a series that ends on an up note is preferred to a series that ends on a down note because people like to defer gratification so that they may savor positive outcomes similarly people apparently have a preference for happy endings finally the extant literature on recency effects would predict that the last event in a series should have a disproportionate influence on overall affect our model relies on a shift in the reference point to explain how a surprising reversal of an event will lead to a nonzero evaluation of the sequence we suggest that people s reference points shift immediately but imperfectly after a stimulus is presented intuitively this implies that the first stimulus will shift the reference point in its direction as a result of which the evaluation of a sequence of events in which an initial event is unexpectedly reversed will be more favorable if the first event is a loss than if it is a gain this model captures the unanticipated nature of the second event i e the surprise element by allowing the first event to move the reference point consequently by the time the next event occurs the reference point has been updated as a result of which the zero economic outcome of the sequence yields nonzero utility we further posit that the magnitude of the reference point shift should be affected by the time elapsed between the two stimuli specifically the reference point shifts gradually with time until it is fully updated consequently the final affective state of the sequence is also a function of the temporal distance between the two events the main predictions of the model were empirically supported first in a survey using a mall intercept sample subsequently we conducted a study of student subjects involving a coin tossing game in which real money was at stake and in which subjects in one condition experienced the second outcome after a two day delay our results from this second study supported the model s prediction regarding the impact of the elapsed time between the events the experimental tasks involved surprising reversals of initial outcomes thus ensuring that savoring dread types of explanations which require that subjects anticipate the second event could not be operating finally in a series of three follow up studies we tested the claim that the magnitude of outcomes would have an impact on observed affect and consistent with our theory and contrary to recency predictions we observed similar results across different magnitudes while theoretically interesting we should also note that our research is of potential pragmatic significance people s reactions to a series of events is of considerable interest to marketers desirous of generating enhanced attitude affect purchase intention and the like without offering economic inducements such as rebates coupons or other costly discounts additionally public policy officials may be interested in protecting people from being manipulated into purchasing a product simply because of changes in the sequence in which a series of offers is made by the merchant

uncertainty learning and heterogeneity in international environmental agreements this paper concerns the formation of international environmental agreements under uncertainty about environmental damage with different models of learning complete learning partial learning or no learning the results of the existing literature are generally pessimistic the possibility of either complete or partial learning generally reduces the level of global welfare that can be achieved from forming an iea relative to no learning that literature regards uncertainty as a parameter common to all countries so that countries are identical ex ante as well as ex post in this paper we extend the literature to the case where there is no correlation between damage costs across countries each country is uncertain about a particular parameter in our case the benefit cost ratio drawn from a common distribution but ex post each country s realized parameter value is independently drawn consequently while countries remain identical ex ante they may be heterogeneous ex post we show that this change reinforces the negative conclusions about the effects of partial learning on international environmental agreements but under certain conditions moderates the negative conclusions about the effects of complete learning

the stability likelihood of an international climate agreement results derived from empirical analyses on the stability of climate coalitions are usually very sensitive to the large uncertainties associated with the benefits and costs of climate policies this paper provides the methodology of stability likelihood sl that links uncertainties about benefits and costs of climate change to the stability of coalitions we show that the concept of sl improves upon the robustness and interpretation of stability analyses moreover our numerical application qualifies conclusions from a recent strand of literature based on stylised models with ex ante symmetric players that learning has a negative impact on the success of coalition formation in context of uncertainty

global environmental risks the need to manage climate risks is not a new it has shaped social institutions for many centuries in medieval england a peasant farmer s land was broken into many widely dispersed parcels economic historians interpret this as a way of hedging climate risk see references in bromley 9 land in different locations would be affected differently by droughts floods and frosts by spreading land holdings over different locations as well as by organizing agricultural cooperatives and buying insurance farmers have managed climate risk for many centuries

duopoly information equilibrium cournot and bertrand abstract in a duopoly model where firms have private information about an uncertain linear demand it is shown that if the goods are substitutes not to share information is a dominant strategy for each firm in bertrand cournot competition if the goods are complements the result is reversed furthermore the following welfare results are obtained 1 i with substitutes in cournot competition the market outcome is never optimal with respect to information sharing but it may be optimal in bertrand competition if the products are good substitutes with complements the market outcome is always optimal 2 ii bertrand competition is more efficient than cournot competition 3 iii the private value of information to the firms is always positive but the social value of information is positive in cournot and negative in bertrand competition

using cumulative prospect theory to explain anomalous crop insurance coverage choice farmers decisions about how much crop insurance to buy are not generally consistent with expected utility maximization taking into account both marginal risk benefits and marginal subsidy effects suggests that most farmers have chosen lower coverage levels than would be predicted by standard models by modeling financial outcomes as gains and losses cumulative prospect theory offers an alternative framework to perhaps better understand farmers purchase decisions the role of the reference point that defines outcomes as either a gain or a loss the degree of loss aversion curvature of the value function and the probability weighting function in determining optimal crop insurance coverage levels are explored for three representative farms calibrated to 2009 conditions loss aversion and how crop insurance is framed through choice of the reference point are shown to be the key factors that determine whether predictions from prospect theory are consistent with observed crop insurance coverage choices when crop insurance is framed as a tool to manage farm risk then optimal choices under prospect theory are not consistent with observed choices if crop insurance is framed as a stand alone investment where a loss is felt if the indemnity received is less than the premium paid then prospect theory can generate optimal coverage level choices that are largely consistent with observed decisions this result is shown to be robust to changes in parameterizations as long as loss aversion is maintained and if curvature of the value function is accompanied by decision weights that overweight low probability outcomes

precautionary savings and the permanent income hypothesis this paper derives the explicit solution of a dynamic stochastic optimal consumption problem for infinitely lived agents whose preferences exhibit in the presence of non diversifiable labour income uncertainty a constant elasticity of intertemporal substitution and constant absolute risk aversion the constancy of the elasticity of intertemporal substitution which implies that marginal utility at zero consumption is infinite guarantees that the non negativity constraint on consumption is never binding along the optimal path the assumption of constant absolute risk aversion allows an explicit computation of human wealth and provides a simple representation of the precautionary savings motive

measuring producers risk preferences a global risk attitude construct in applied agricultural economic research various risk attitude elicitation techniques are used here we investigate whether risk attitude measures rooted in the expected utility framework are related to measures rooted in the multi item scale framework using a second order factor analytical model and data obtained from personal computer guided interviews with 373 farmers we investigate whether the common variance among the latent risk attitude measures can be accounted for by a global risk attitude construct we find that the different risk attitude measures are related and that the global risk attitude construct is significantly related to farmers intention to use futures contracts our research suggests that farmers risk attitude is a higher order characteristic that cannot be effectively extracted by a single measure in empiricalstudies deal ing with risk risk attitudes and producers market behavior various risk attitude measures are used two major approaches to quantify directly farmers risk attitudes can be distinguished measures derived from the expected utility framework and measures derived from responses to multi item scales e g antle chavas and holt goodwin and schroeder saha shumway and talpaz smidts the purpose of this research is to test whether risk attitude measures rooted in the expected utility framework are related to the risk attitude scales rooted in the multiitem scale approach and if so whether these risk attitude measures share a common

can uncertainty alleviate the commons problem global commons problems such as climate change are often affected by severe uncertainty the paper examines the effect of uncertainty on pollution emissions and welfare in a strategic context we find that emissions are always lower under uncertainty than under certainty reflecting risk reducing considerations we show that uncertainty can have a net positive impact on the welfare of risk averse polluters we extend the analysis to increases in risk increases in risk aversion and to risk heterogeneity jel d81 c72 q54 h23

formation and adaptation of reference prices in grain marketing an experimental study this study aimed to explore how producers reference prices are formed and adapt over time and how they affect marketing decisions results indicate that producers focus on three major variables to form their reference prices the current market price the highest price to date and their expectation about price behavior further they update their reference prices during the marketing season mainly in response to changes in current market prices their own expectations about price behavior and the general price trend finally our findings suggest that producers marketing decisions are based on the spread between current market price and reference price the general market trend and price expectation

negotiating environmental agreements under ratification constraints abstract we analyze the impact of ratification constraints on the optimal terms of international environmental agreements ieas for this we combine the literature on ieas with the public choice literature on two level games by also incorporating uncertain preferences of the pivotal voter in the ratification stage we make several important contributions i we contribute to a more realistic modeling of the temporal structure of international agreements ii we show a surprising yet intuitive non monotonic relationship between the optimal commitment level and the variance of ratification decisions iii we identify reasons to expect a larger number of countries to join international negotiations than predicted by most of the coalition formation literature based on a representative agent model ratification constraints thereby can improve the welfare gains from stable international agreements

the disposition effect in securities trading an experimental analysis the disposition effect is the tendency to sell assets that have gained value winners and keep assets that have lost value losers disposition effects can be explained by the two features of prospect theory the idea that people value gains and losses relative to a reference point the initial purchase price of shares and the tendency to seek risk when faced with possible losses and avoid risk when a certain gain is possible our experiments were designed to see if subjects would exhibit disposition effects subjects bought and sold shares in six risky assets asset prices fluctuated in each period contrary to bayesian optimization subjects did tend to sell winners and keep losers when the shares were automatically sold after each period the disposition effect was greatly reduced

uncertainty learning and international environmental agreements the role of risk aversion this paper analyses the formation of international environmental agreements ieas under uncertainty learning and risk aversion it bridges two strands of the iea literature i the role of learning when countries are risk neutral ii the role of risk aversion under no learning combining learning and risk aversion seems appropriate as the uncertainties surrounding many international environmental problems are large often highly correlated e g climate change but are gradually reduced over time through learning the paper analyses three scenarios of learning a key finding is that risk aversion can change the ranking of these three scenarios of learning in terms of welfare and membership in particular the negative conclusion about the role of learning in a strategic context under risk neutrality is qualified when countries are significantly risk averse then it pays them to wait until uncertainties have been largely resolved before joining an iea this may suggest why it has been so difficult to reach an effective climate change agreement

piercing the veil of uncertainty in transboundary pollution agreements this paper addresses the question of how uncertainty in costs and benefits affects the difficulty of reaching a voluntary agreement among sovereign states a measure of difficulty is constructed related to side payments necessary to make an agreement a pareto improving move using a simple model it is shown that uncertainty actually makes agreement easier

on the concavity of the consumption function at least since keynes 1935 many economists have had the intuition that the marginal propensity to consume out of wealth declines as wealth increases nonetheless standard perfect certainty and certainty equivalent versions of intertemporal optimizing models of consumption imply a marginal propensity to consume that is unrelated to the level of household wealth we show that adding income uncertainty to the standard optimization problem induces a concave consumption function in which as keynes suggested the marginal propensity to consume out of wealth or transitory income declines with the level of wealth

international aspects of pollution control pollution is a by product of production is only gradually dissolved by the environment and crosses national borders the market outcome ignores the adverse effects of pollution and thus yields higher levels of output and pollution than would prevail under a supranational social planner which does care about pollution in practice governments often do not cooperate and this leads to outcomes of pollution and production in between the market outcomes and the outcomes under supra national social planning absence of precommitment leads to lower emission charges less cleaning up activities and more pollution appropriate levels of emission charges under the various outcomes are a result of this analysis attention is also paid to investment in clean technology the debate between optimists who believe that higher production is compatible with sound environmental policy and pessimists can be analysed in this way