dusenberry s ratcheting of consumption optimal dynamic consumption and investment given intolerance for any decline in standard of living duesenberry s ratcheting consumption demand is derived as a feature of the optimal dynamic consumption and investment policy given extreme habit formation that prevents consumption from falling over time preferences are in effect non time separable extended real valued von neumann morgenstern preferences consumption increases each time wealth reaches a new maximum risky investment is proportional to the excess of wealth over the perpetuity value of current consumption extensions constrain the net rate of decrease in consumption with a constant other than zero add more consumption goods and constrain on the maximal holding of the risky asset as a proportion of wealth these strategies may be useful for the management of university endowments participatory investment accounts and risky arbitrage funds

can costs of consumption adjustment explain asset pricing puzzles we investigate grossman and laroque s 1990 conjecture that costs of adjusting consumption can account in part for the empirical failure of the consumptionbased capital asset pricing model ccapm we incorporate small fixed costs of consumption adjustment into a ccapm with heterogeneous agents we find that undetectably small consumption adjustment costs can account for much of the discrepancy between the observed variance of nondurable aggregate consumption growth and the predictions of the ccapm and can partially reconcile nondurable consumption data with the observed equity premium we conclude that the ccapm s implications are nonrobust to extremely small adjustment costs the consumption based capital asset pricing models ccapms 1 of lucas 1978 breeden 1979 and grossman and shiller 1982 have difficulty matching the high volatility of equity returns and the high mean equity premium found in u s data first the variance of the ccapm asset pricing kernel is too low to generate plausible equity return volatility more precisely hansen and jagannathan 1991 and cochrane and hansen 1992 show that for any conjectured pricing kernel mean the variance of the kernel is too low to satisfy the hansen jagannathan bounds without implausibly high risk aversion or substantial habit formation 2 second the covariance between the ccapm asset pricing kernel and excess equity returns is too low to generate a plausible equity premium more precisely let us define ep as follows

this time it s different an inevitable decline in world petroleum production will keep oil product prices high causing military conflicts and shifting wealth and power from democracies to authoritarian regimes abstract there is virtual agreement among geologists that world production of conventional oil will peak at some point in the future oil after all is a finite resource while demand will only grow over time geologists disagree however exactly when the peak will occur using data from the international energy agency the us department of energy the association for the study of peak oil and gas and petroleum industry sources we argue that conventional oil production will reach a worldwide maximum within the next 5 10 years earlier than generally estimated thus leaving a very short time frame within which to plan for conversion to alternative sources of energy unless planning is initiated immediately the united states and other western democracies will see their positions in the global economy undercut as military conflicts over limited energy resources increase and wealth and power are shifted to authoritarian regimes in russia venezuela africa and the middle east

a general equilibrium model of portfolio insurance this article examines the effects of portfolio insurance on market and asset price dynamics in a general equilibrium continuous time model portfolio insurers are modeled as expected utility maximizing agents martingale methods are employed in solving the individual agents dynamic consumption portfolio problems comparisons are made between the optimal consumption processes optimally invested wealth and portfolio strategies of the portfolio insurers and normal agents at a general equilibrium level comparisons across economies reveal that the market volatility and risk premium are decreased and the asset and market price levels increased by the presence of portfolio insurance article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

conscientious vs ambivalent consumers do concerns about energy availability and climate change influence consumer behaviour abstract energy availability and climate change are interrelated concerns with economic components they need to be addressed by policy makers and they require changes in energy consumption this study examines whether concerns about energy availability and climate change influence consumer behaviour policy perceptions and beliefs about future energy consumption this question is investigated by analysing data from the eurobarometer 75 4 a comprehensive survey of citizens from all countries of the european union that was conducted in june 2011 n 26 840 the regression results show that people concerned about climate change were significantly more likely to take action to mitigate climate change and to be more favourably disposed towards energy policies and future changes in energy consumption than people who were not concerned about climate change on the other hand people who were concerned about energy availability undertook fewer actions and neither supported energy policies nor believed in future changes in energy consumption this surprising finding raises questions regarding the adequate communication of energy availability and policies to the public in the european union

the analytic valuation of american options no analytic solutions exists for the valuation of american options written on futures contracts and foreign currencies for which early exercise may be optimal this article formulates the american option valuation problem in economically and mathematically meaningful ways this enables us to derive valuation formulas for american options the properties associated with the optimal exercise boundary are examined and a numerical technique to implement the valuation formulas is presented article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

optimal portfolio choice for long horizon investors with nontradable labor income this paper examines how risky labor income and retirement affect optimal portfolio choice with idiosyncratic labor income risk the optimal allocation to stocks is unambiguously larger for employed investors than for retired investors consistent with the typical recommendations of investment advisors increasing idiosyncratic labor income risk raises investors willingness to save and reduces their stock portfolio allocation towards the level of retired investors positive correlation between labor income and stock returns has a further negative effect and can actually reduce stockholdings below the level of retired investors financial advisors typically recommend that their customers invest more in stocks than in safe assets when they are working and to shift their investments towards safe assets when they retire jagannathan and kocherlakota 1996 malkiel 1996 by contrast the standard academic models of portfolio choice merton 1969 1971 samuelson 1969 show that retirement is irrelevant for portfolio decisions if investment opportunities are constant and human capital is tradable in this case the fraction of wealth optimally invested in risky assets should be constant over the lifetime of an individual recent research building on the pioneering work by merton 1971 shows that time varying investment opportunities result in portfolio rules with an intertemporal hedging component whose magnitude depends on the investment horizon of the investor kim and omberg 1996 balduzzi and lynch 1997 brennan schwartz and lagnado 1997 brandt 1999 campbell and viceira 1999 2001 barberis 2000 with time variation in investment opportunities retirement and death play an instrumental role as events that exogenously fix the individual s investment horizon more importantly retirement also marks the time at which individuals stop working and thereafter must live off their lifetime savings and possibly transfers from this perspective retirement matters for portfolio choice

on estimating the option value of preserving a wilderness area in this paper option pricing theory is used to analyse whether or not to preserve a wilderness area a numerical approach is demonstrated that can be applied to any generalized stochastic process the impact of assuming that amenity value follows a logistic process rather than geometric brownian motion is considered the calculation of critical levels for amenity value necessary to justify preserving a wilderness area such as the killarney provincial park in ontario or the headwaters forest in california is demonstrated the impact of changing the assumed growth and volatility of amenity value is also examined jel classifcation d81 q26 ce memoire utilise la theorie de la tarification d une option pour analyser si on doit preserver un espace naturel on utilise une approche numerique qui peut etre appliquee a tout processus stochastique generalise on examine l impact de possibilites que le profil de la valeur de la ressource dans la temps suive un processus logistique plutot qu un pattern geometrique de type brownien le texte montre le calcul des niveaux critiques de la valeur de la ressource qui seraient necessaires pour justifier la preservation d une espace naturel comme le parc provincial killarney en ontario ou les forets headwaters en californie l impact de postulats differents quant a la croissance et a la volatilite de la valeur de la ressource est examine

optimal portfolio choice under loss aversion this paper analyzes the optimal investment strategy for loss averse investors assuming a complete market and general ito processes for the asset prices the loss averse investor follows a partial portfolio insurance strategy when the investor s planning horizon is short less than 5 years he or she considerably reduces the initial portfolio weight of stocks compared to an investor with smooth power utility the empirical section of the paper estimates the level of loss aversion implied by historical u s stock market data using a representative agent model we find that loss aversion and risk aversion cannot be disentangled empirically

energy return on energy invested eroi oil prices and energy transitions very little work has been done so far to model test and understand the relationship between oil prices and eroi over time this paper investigates whether a declining eroi is associated with an increasing oil price and speculates on the implications of these results on oil policy a model of the relationship between eroi and oil market prices was developed using basic economic and physical assumptions and non linear least squares regression models to correlate oil production price with eroi using available data from 1954 1996 the model accurately reflects historical oil prices 1954 1996 and it correlates well with historical oil prices 1997 2010 if a linear extrapolation of eroi decline is assumed as eroi declines below 10 highly non linear oil price movements are observed increasing physical oil scarcity is already providing market signals that would stimulate a transition away from oil toward alternative energy sources but price signals of physical oil scarcity are not sufficient to guarantee smooth transitions to alternative fuel sources especially when there is insufficient oil extraction technology development a declining mark up ratio a non linear eroi cost of production relationship and a non linear eroi price relationship

portfolio choice and trading volume with loss averse investors this paper presents a model of portfolio choice and stock trading volume with lossaverse investors the demand function for risky assets is discontinuous and non monotonic as wealth rises beyond a threshold investors follow a generalized portfolio insurance strategy this behavior is consistent with the evidence in favor of the disposition effect in addition loss averse investors will not hold stocks unless the equity premium is quite high the elasticity of the aggregate demand curve changes substantially depending on the distribution of wealth across investors in an equilibrium setting the model generates positive correlation between trading volume and stock return volatility but suggests that this relationship should be non linear

risk and resilience in the nigerian oil sector the economic effects of pipeline sabotage and theft abstract political unrest in the niger delta has long been viewed as a hurdle for extracting maximum value from nigeria s oil resources recently investors and policymakers have laid blame for sector under performance on pipeline sabotage and theft and sounded the alarm for an impending oil crisis however our understanding of the economic effects of social action against oil companies is incomplete rigorous analysis has not heretofore been offered as evidence for such dire futures despite the obvious risk of pipeline interdiction price dynamics and aggregate production respond minimally to pipeline interdiction based on quantitative analysis of the relationship among price production and pipeline interdiction from multiple data sources covering different time intervals monthly data from 2005 to 2014 and annual data from 1999 to 2013 we find no evidence of significant effects of pipeline interdiction on production and a weak relationship between pipeline interdiction and bonny light crude prices reported losses in product are substantial but there is no evidence of statistically significant impacts on price or production in the aggregate explanations for this counterintuitive result are cast in terms of sector resilience the implications of this finding for producer risk and the likelihood of an impending oil crisis are discussed

optimal risk sharing and borrowing constraints in a continuous time model with limited commitment abstract we study a continuous time version of the optimal risk sharing problem with one sided commitment in the optimal contract the agent s consumption is a time invariant strictly increasing function of a single state variable the maximal level of the agent s income realized to date we characterize this function in terms of the agent s outside option value function and the discounted amount of time in which the agent s income process is expected to reach a new to date maximum under constant relative risk aversion we solve the model in closed form optimal consumption of the agent equals a constant fraction of his maximal income realized to date in the complete markets implementation of the optimal contract the alvarez jermann solvency constraints take the form of a simple borrowing constraint familiar from the bewley aiyagari incomplete markets models

marginal valuation of charismatic species implications for conservation most contingent valuation studies focus on total willingness to pay wtp as a measure of welfare change for policy involving species preservation however it is important to distinguish between the benefits of preventing a species from going extinct and the benefits of preserving numbers above the minimum viable population mvp level once mvp is exceeded marginal wtp becomes relevant these propositions are illustrated for the case of one charismatic species whose management is much debated minke whales in the northeast atlantic ocean it is shown that for a given estimate of total preservation value strict conservation and extinction can both be optimal this finding highlights the importance of collecting marginal values in contingent valuation surveys

optimal consumption and portfolio policies when asset prices follow a diffusion process abstract we consider a consumption portfolio problem in continuous time under uncertainty a martingale technique is employed to characterize optimal consumption portfolio policies when there exist nonnegativity constraints on consumption and on final wealth we also provide a way to compute and verify optimal policies our verification theorem for optimal policies involves a linear partial differential equation unlike the nonlinear partial differential equation of dynamic programming the relationship between our approach and dynamic programming is discussed we demonstrate our technique by explicitly computing optimal policies in a series of examples in particular we solve the optimal consumption portfolio problem for hyperbolic absolute risk aversion utility functions when the asset prices follow a geometric brownian motion the optimal policies in this case are no longer linear when nonnegativity constraints on consumption and on final wealth are included by these examples one can see that our approach is much easier than the dynamic programming approach

a comparative study of portfolio insurance abstract this paper undertakes a comparative study of portfolio insurance under a variety of modeling strategies specifically we focus on portfolio insurers who derive utility from horizon wealth with marginal utility tending smoothly to infinity at some pre specified floor we solve for the optimal consumption portfolio wealth of these portfolio insurers and compare with constrained portfolio insurers and normal agents general equilibrium conditions are contrasted under pure exchange and production type models while the market price level is unambiguously increased under pure exchange under production the effect on market level is state dependent in both models the market volatility and risk premium are decreased by portfolio insurance the paper also investigates the possible relationship between portfolio insurance type trading strategies and market volatility

income risk borrowing constraints and portfolio choice economic theory suggests that uninsurable income risk and the expectation of future borrowing constraints can reduce the share of risky assets in a household s portfolio if the utility function exhibits decreasing absolute risk aversion and decreasing prudence an individual will reduce his exposure to rate of return risks when confronted with other independent risks if there are transaction costs the expectation of future borrowing constraints should induce individuals to keep a lower proportion of their wealth in the form of illiquid and risky assets the authors find support for these propositions in a cross section of italian households copyright 1996 by american economic association

international management strategies for a straddling fish stock a bio economic simulation model of the norwegian spring spawning herring fishery in this paper a three country dynamic bio economic simulation model is presented for the spring spawning herring fishery the international spring spawning herring fishery based on potentially one of the most valuable fish stocks in the world is currently recovering from a severe depletion of the stock and subsequent harvesting moratorium management of the herring fishery is complicated by its multi nation exploitation due to the highly migratory behaviour of the species moving between several coastal state zones exclusive economic zones eez s and the high seas ocean loop based on extensive work invested on analysing both the biology of the herring stock and the fisheries economics around its exploitation we study here the profiles of different multi agent management schemes simulating catch levels stock size and profit potentials of alternative management strategies the stock dynamics are described by a linear discrete time age structured population model and the economics are presented by a rent maximising model with constant price of herring catch and different costs of harvesting and efficiency levels for the different national fleets the simulations carried out over several decades show that the benefits of international co operation far exceed the returns of a competitive open access fishery

estimating coal production peak and trends of coal imports in china more than 20 countries in the world have already reached a maximum capacity in their coal production peak coal production such as japan the united kingdom and germany china home to the third largest coal reserves in the world is the world s largest coal producer and consumer making it part of the big six at present however china s coal production has not yet reached its peak in this article logistic curves and gaussian curves are used to predict china s coal peak and the results show that it will be between the late 2020s and the early 2030s based on the predictions of coal production and consumption china s net coal import could be estimated for coming years this article also analyzes the impact of china s net coal import on the international coal market especially the asian market and on china s economic development and energy security

risk aversion and planning horizons a number of empirical studies seem to reject the additive separability of preferences that is assumed in most theoretical models of the life cycle we show that when additive separability is abandoned and interactions between consumptions at different dates are taken into account an interesting relation emerges between risk aversion and length of the planning horizon specifically we show that when consumptions at different dates are specific substitutes risk aversion increases with horizon length this may explain the surprising empirical finding that individuals seem to increase the share of wealth held in risky assets as they become older jel d11 d91 g11

a generalization of dybvig s result on portfolio selection with intolerance for decline in consumption abstract in this note we show the following result of dybvig 1995 is valid for a general von neumann morgenstern utility function for an agent who does not tolerate a decline in consumption the optimal investment out of discretionary wealth in excess of the perpetuity value of current consumption in the risky asset does not depend on the risk aversion coefficient of her felicity function locally when she does not adjust her consumption the homotheticity assumption is not required an implication of our result is that if an economic agent exhibits non time separable preference due to intertemporal linkage of consumption her risk taking over a short time period can be independent of her felicity function

an analysis of china s coal supply and its impact on china s future economic growth many people believe that china s economic growth can continue almost indefinitely for a manufacturingbased economy such as china s to continue to grow it needs an adequate supply of inexpensive energy to date this energy growth has primarily come from coal but china s indigenous coal supplies are now falling short of the amount needed to support this growth in this situation the status of china s future coal supply will be very important for china s future economic development our analysis shows that china s ultimate recoverable coal reserves equal 223 6 10 9 mt and its production will peak between 2025 and 2030 with peak production of approximately 3 9 10 9 mt the extent to which china can import coal in the future is uncertain with rising coal demand this combination is likely to create a significant challenge to china s future economic development

not just minor forest products the economic rationale for the consumption of wild food plants by subsistence farmers abstract non timber forest products ntfps make an important contribution to the livelihood of the households who gather and consume them in particular the consumption of ntfps allows gatherers to live with lower amounts of cash than if they had to buy in the market what they can obtain from the forest for free understanding the economic value of non marketed ntfps helps determine the true income of the gatherers and the amount of extra cash that they would need if they could no longer gather ntfps it also helps ascertain the true value of the standing forest leading to more rational decisions about its alternative uses yet the ntfps that are not marketed are often ignored when estimates are made of the economic importance of ntfps to rural populations this article briefly describes five methods for estimating the value of non marketed wild edible plants it then compares two of these methods with data from one month of fieldwork in two pwo karen villages in thung yai naresuan wildlife sanctuary in western thailand the article concludes that wild food plants remain a preferred alternative to commercial food crops because gathering wild food plants is a much more efficient use of time than engaging in the market economy in order to purchase commercial food crops

what energy levels can the earth sustain abstract several official reports on future global primary energy production and use develop scenarios which suggest that the high energy growth rates of the 20th century will continue unabated until 2050 and even beyond in this paper we examine whether any combination of fossil nuclear and renewable energy sources can deliver such levels of primary energy around 1000 ej in 2050 we find that too much emphasis has been placed on whether or not reserves in the case of fossil and nuclear energy or technical potential in the case of renewable energy can support the levels of energy use forecast in contrast our analysis stresses the crucial importance of the interaction of technical potentials for annual production with environmental factors social political and economic concerns and limited time frames for implementation in heavily constraining the real energy options for the future together these constraints suggest that future energy consumption will be significantly lower than the present level

risk aversion wealth and background risk we use household survey data to construct a direct measure of absolute risk aversion based on the maximum price a consumer is willing to pay for a risky security we relate this measure to consumer s endowments and attributes and to measures of background risk and liquidity constraints we find that risk aversion is a decreasing function of the endowment thus rejecting cara preferences we estimate the elasticity of risk aversion to consumption at about 0 7 below the unitary value predicted by crra utility we also find that households attributes are of little help in predicting their degree of risk aversion which is characterized by massive unexplained heterogeneity we show that the consumer s environment affects risk aversion individuals who are more likely to face income uncertainty or to become liquidity constrained exhibit a higher degree of absolute risk aversion consistent with recent theories of attitudes toward risk in the presence of uninsurable risks jel d1 d8

portfolio optimization under loss aversion abstract we present an integrated methodological approach for selecting portfolios the proposed methodology is focused on incorporation of investor s preferences in the mean risk framework we propose a risk measure calculated with the downside part of the portfolio return distribution which we argue captures better the practical behavior of the loss averse investor we establish its properties study the link with stochastic dominance criteria point out the relations with conditional value at risk and lower partial moment of first order and give the explicit formula for the case of scenario based portfolio optimization the proposed methodology involves two stages firstly the investment opportunity set efficient frontier is determined and secondly one single preferred efficient portfolio is selected namely the one having the highest expected utility value three classes of utility functions with loss aversion corresponding to three types of investors are considered the empirical study is targeted on assessing the differences between the efficient frontier of the proposed model and the classical mean variance mean cvar and mean lpm1 frontiers we firstly analyze the loss of welfare incurred by using another model instead of the proposed one and measure the corresponding gain loss of utility secondly we assess how much the portfolios really differ in terms of their compositions using a dissimilarity index based on the 1 norm we describe and interpret the optimal solutions obtained and emphasize the role and influence of loss aversion parameters values and of constraints three types of constraints are studied no short selling allowed a certain degree of diversification imposed and short selling allowed

global energy crunch how different parts of the world would react to a peak oil scenario peak oil theory predicts that oil production will soon start a terminal decline most authors imply that no adequate alternate resource and technology will be available to replace oil as the backbone resource of industrial society this article uses historical cases from countries that have gone through a similar experience as the best available analytical strategy to understand what will happen if the predictions of peak oil theorists are right the author is not committed to a particular version of peak oil theory but deems the issue important enough to explore how various parts of the world should be expected to react from the historical record he is able to identify predatory militarism totalitarian retrenchment and socioeconomic adaptation as three possible trajectories

effective climate energy solutions escape routes and peak oil abstract many well intended climate energy strategies are ineffective in the absence of serious environmental regulation this holds among others for direct support of clean energy voluntary energy conservation technical standards on a limited set of products unilateral stringent carbon pricing and awaiting peak oil as a climate strategy all of these suffer from escape routes that indirectly increase co2 emissions and thus make the original strategy ineffective on the other hand environmental regulation alone may lead to a myopia bias stimulating early dominance of cost effective technologies and a focus on incremental innovations associated with such technologies rather than on radical innovations although adopting a partial viewpoint keeps the analysis simple we urgently need a more inclusive systems perspective on climate solutions this will allow the formulation of an effective climate policy package that addresses the various escape routes

optimal asset allocation under linear loss aversion abstract we study the asset allocation of a linear loss averse la investor and compare it to the more traditional mean variance mv and conditional value at risk cvar investors first we derive conditions under which the la problem is equivalent to the mv and cvar problems and solve analytically the two asset problem of the la investor for a risk free and a risky asset then we run simulation experiments to study properties of the optimal la and mv portfolios under more realistic assumptions we find that under asymmetric dependence la portfolios outperform mv portfolios provided investors are sufficiently loss averse and dependence is large finally using 13 eu and us assets we implement the trading strategy of a linear la investor who reallocates his her portfolio on a monthly basis we find that la portfolios clearly outperform mv and cvar portfolios and that incorporating a dynamic update of the la parameters significantly improves the performance of la portfolios

higher order risk attitudes demographics and financial decisions we conduct an experiment to study the prevalence of the higher order risk attitudes of prudence and temperance in a large demographically representative sample as well as in a sample of undergraduate students participants make pairwise choices between lotteries of the form proposed by eeckhoudt and schlesinger 2006 the choices in these lotteries isolate prudent from imprudent and temperate from intemperate behavior we relate individuals risk aversion prudence and temperance levels to demographics and financial decisions we observe that the majority of individuals decisions are consistent with risk aversion prudence and temperance in both the student and the demographically representative sample an individual s level of prudence is predictive of his wealth saving and borrowing behavior outside of the experiment while temperance predicts the riskiness of portfolio choices our findings suggest that the coefficient of relative prudence for a representative individual is approximately equal to two

portfolio selection with consumption ratcheting abstract in this paper we study the portfolio selection problem of a finite lived agent who does not tolerate a decline in standard of living the preference can be regarded as exhibiting extreme form of habit formation and also related to loss aversion in the prospect theory we show that the agent s optimal portfolio exhibits a trend chasing behavior and the portfolio share of the risky asset fluctuates between 0 and the value of an unconstrained individual the fluctuations do not attenuate as time gets near the end of the planning horizon we also explore implications of the model for asset pricing and show that the model has a potential to match better the recent us data than traditional habit models we provide a complete solution to the problem by considering a transformed problem which is similar in its formal structure to an irreversible incremental investment problem and equivalent to an infinite series of optimal stopping problems

value of recreational fishing in the brazilian pantanal a travel cost analysis using count data models abstract recreational fishing value of the brazilian pantanal is measured using travel cost method tcm we compare non linear poisson and negative binomial count data models to estimate recreational fishing trip demands the count data and truncated models are used primarily to account for non negative integer and truncation properties of recreational fishing trips as suggested by the recreation valuation literature the results reveal that non linear and truncated count data models perform relatively well in our study the economic values of recreational fishing in terms of consumer surplus cs are derived using non linear and truncated models we estimate the cs values from 540 54 to 869 57 per trip resulting in the total social welfare estimate range from 35 to 56 million the study demonstrates a relatively high value of recreational fishing in the pantanal in comparison to similar studies conducted in other parts of the world the findings of this study would be important for resource management decisions in the pantanal and could serve as a reference in valuing similar resources in other ecosystems around the world