learning to believe in sunspots a number of authors have shown that competitive economies may possess sunspot equilibria that is rational expectations equilibria in which purely extrinsic uncertainty affects equilibrium prices and allocations 2 such results demonstrate that it does not require a lack of faith in the rationality of market participants to believe that competitive markets may be subject to purely speculative fluctuations driven solely by expectations 3 the mere existence of sunspot equilibria as solutions to a system of marketclearing conditions however might not be judged sufficient to indicate that competitive markets with rational participants could ever be subject to speculative instability the sunspot equilibria represent states of affairs in which agents act differently in the case of different realizations of the sunspot variable and it is rational for each agent to do so but it might be thought unlikely that the beliefs of all the participants in the market could ever come to be coordinated so as to bring about an equilibrium of that kind it is rational to believe that sunspots convey information about future states of affairs once the economy is in a sunspot equilibrium but why would rational agents ever begin to believe in such a thing so as to create the conditions under which the belief is rational in order to address such a question one must go beyond the mere statement of the conditions for equilibrium and discussion of what states of affairs satisfy them one must specify an explicit dynamic process according to which the beliefs of agents adjust when out of equilibrium any exercise of this kind is necessarily unsatisfactory as there is no univocal meaning for the postulate of rational behavior outside of an equilibrium it may well be the case that

pest externalities from agricultural inputs agricultural inputs such as water pesticide and even time may have the unintended effect of stimulating some pest populations leading to crop losses a conceptual model is developed to contrast optimal use of pesticide and nonpesticide inputs with myopic use patterns which ignore pest externalities under most conditions optimal management is found to entail reduced input levels these issues are illustrated for imperial valley cotton using biological simulation correct calculation of the relative profitability of conventional and integrated pest management techniques such as a shortened growing season are found to depend crucially on whether pest externalities are taken into account

design and analysis of simulated consumer choice or allocation experiments an approach based on aggregate data the authors integrate concepts in conjoint analysis and discrete choice theory in econometrics to develop a new approach to the design and analysis of controlled consumer choice or resource allocat

boundedly rational versus optimization based models of strategic thinking and learning in games harstad and selten s article in this forum performs a valuable service by highlighting the dominance of optimization based models over boundedly rational models in modern microeconomics and questioning whether optimization based models are a better way forward than boundedly rational models this article complements rabin s response to harstad and selten focusing on modeling strategic behavior i consider harstad and selten s examples and proposed boundedly rational models in the light of modern behavioral economics and behavioral game theory commenting on the challenges that remain and the most promising ways forward

imperfect choice or imperfect attention understanding strategic thinking in private information games to understand the thinking process in private information games we use mousetracking to record which payoffs subjects attend to the games have three information states and vary in strategic complexity subjects consistently deviate from nash equilibrium choices and often fail to look at payoffs which they need to in order to compute an equilibrium response choices and lookups are similar when stakes are higher when cluster analysis is used to group subjects according to lookup patterns and choices three clusters appear to correspond approximately to level 3 level 2 and level 1 thinking in level k models and a fourth cluster is consistent with inferential mistakes as for example in qre or cursed equilibrium theories deviations from nash play are associated with failure to look at the necessary payoffs the time durations of looking at key payoffs can predict choices to some extent at the individual level and at the trial by trial level

input demand under yield and revenue insurance previous studies disagree on the effects of insurance on fertilizer application rates the effect of increased fertilizer on the probability of low yields primarily determines whether fertilizer and insurance are substitutes or complements we estimate conditional distributions of corn yields to determine if the technical relationship between yields and fertilizer supports the hypothesis that insurance increases optimal application rates our results indicate no support for this hypothesis at all nitrogen fertilizer rates and reasonable levels of risk aversion nitrogen fertilizer and insurance are substitutes suggesting that those who purchase insurance are likely to decrease nitrogen fertilizer applications

an ideal point probabilistic choice model for heterogeneous preferences this paper presents a new ideal point probabilistic choice model unlike the model suggested by cooper and nakanishi cooper l g m nakanishi 1983 two logit models for external analysis of preferences psychometrika48 4 607 619 which attempts to capture choices via a single ideal point the proposed model though based on aggregate data allows for heterogeneity in preferences by estimating a distribution of ideal points the model accounts for substitutability among choice alternatives and alleviates one of the major sources for the violation of the independence from irrelevant alternatives property it is demonstrated that the final form of the model is a multinomial probit with a covariance matrix that depends on the relative position of the choice alternatives an empirical application is provided and the resulting parameters are compared to the distributions of ideal points and attribute weights obtained via linmap at the individual level and via both the logit and probit versions of the model proposed by cooper and nakanishi at the aggregate level

can economic incentives encourage actual reductions in pesticide use and environmental spillovers chemical pesticides constitute an important input in crop production but their indiscriminate use can impact negatively agricultural productivity human health and the environment recently attention is focused on the use of economic incentives to reduce pesticide use and its related indirect effects the aim of this work is to assess the effectiveness of different economic instruments such as taxes and levies in encouraging farmers to decrease pesticide use and their environmental spillovers a policy simulation model is employed using data from dutch cash crop producers including two pesticide categories that differ in terms of toxicity and pesticides environmental spillovers four different instruments were selected for evaluation pesticide taxes price penalties on pesticides environmental spillovers subsidies and quotas the results of the study indicate that even high taxes and penalties would result in a small decrease in pesticide use and environmental spillovers taxes that differentiate according to toxicity do not lead to substitution of high with low toxicity pesticides subsidies on low toxicity products are not able to affect the use of high toxicity products pesticide quotas are more effective in reducing pesticide use and environmental spillovers

a probabilistic choice model for market segmentation and elasticity structure marketing scholars commonly characterize market structure by studying the patterns of substitution implied by brand switching though the approach is useful it typically ignores the destabilizing

replacement of agricultural price supports by area payments in the european union and the effects on pesticide use this article determines the contribution of recent european union agricultural policy reforms on the use of pesticides our theoretical model extends the multioutput generalization of the lichtenberg zilberman damage control technology model developed by chambers and lichtenberg our empirical analysis uses farm level data for a sample of french farms results suggest that price effects on the use of pesticides are always more elastic than area payment effects this indicates that policy reforms consisting of a reduction in price supports in favor of area payments may reduce application of crop protection inputs such policy changes which represent a certain degree of decoupling took place under the 1992 common agricultural policy reforms

risk preferences and pesticide use by cotton farmers in china abstract despite that insect resistant bt cotton has been lauded for its ability to reduce the use of pesticides studies have shown that chinese bt cotton farmers continue to use excessive amounts of pesticides using results from a survey and an artefactual field experiment we find that farmers who are more risk averse use greater quantities of pesticides we also find that farmers who are more loss averse use lesser quantities of pesticides this result is consistent with our conceptual framework and suggestive evidence where farmers behave in a loss averse manner in the health domain and place more weight on the importance of health over money in the loss domain

ex post flexibility and choice of capacity for loss reduction this paper examines the implications of ex post utilization flexibility for the firm s ex ante choice of capacity to supply a loss reducing input it is shown that the optimal ex ante choice is greater in the presence of flexibility than in the absence of flexibility it is also shown that the total effect of an increase in risk on the ex ante choice includes a flexibility effect when ex post flexibility is present the flexibility effect always tends to increase the demand for capacity

the impact of agricultural biotechnology on yields risks and biodiversity in low income countries abstract this paper shows that the current generation of transgenic crop varieties has significant potential to improve economic welfare in low income countries these varieties might increase crop yields in low income countries in cases when pesticides have not been used they will reduce negative health effects of chemicals when they replace them with low transaction costs appropriate infrastructure and access to intellectual property multiple varieties of transgenics will be introduced the gain from transgenics will be reduced and crop biodiversity may be lost when only a small set of varieties is transgenetically modified the adoption of transgenics will also be affected by risk and credit considerations

bubbles crashes and endogenous expectations in experimental spot asset markets1 spot asset trading is studied in an environment in which all investors receive the same dividend from a known probability distribution at the end of each of t 15 or 30 trading periods fourteen of twenty two experiments exhibit price bubbles followed by crashes relative to intrinsic dividend value when traders are experienced this reduces but does not eliminate the probability of a bubble the regression of changes in mean price on lagged excess bids number of bids minus the number of offers in the previous period p pt a f b 1 o l supports the hypothesis that a e d the one period expected value of the dividend and that f 0 where excess bids is a surrogate measure of excess demand arising from homegrown capital gains losses expectations thus when bt 1 o goes to zero we have convergence to rational expectations in the sense of fama 1970 that arbitrage becomes unprofitable the observed bubble phenomenon can also be interpreted as a form of temporary myopia tirole 1982 from which agents learn that capital gains expectations are only temporarily sustainable ultimately inducing common expectations or priors tirole 1982 four of twenty six experiments all using experienced subjects yield outcomes that appear to the chart s eye to converge early to rational expectations although even in these cases we get 0 and small price fluctuations of a few cents that invite scalping

testing predicted choices against observations in probabilistic discrete choice models probabilistic discrete choice models such as multinomial logit models are widely used to predict changes in market shares or total demand resulting from changes in policy variables under management control these models often are evaluated in terms of their ability to predict choices in a holdout sample this paper presents a new test for comparing predicted and observed choices the results of a monte carlo experiment indicate that the new test has good finite sample properties and high power in several circumstances likely to arise frequently in applications

the econometrics of damage control why specification matters the contribution of damage control agents to production differs fundamentally from that of standard inputs lands labor capital this paper develops an econometric model based on the key characteristics of damage control agents and examines its properties it demonstrates that standard production function specifications overestimate damage control agent productivity and have erroneous implications for the evolution of damage control agent productivity and use in response to changing environments e g the spread of pest resistance it also proposes several alternative specifications and discusses methods for estimating them

optimal pest control in agriculture abstract based on economic methodology we model an ecosystem with two species in predator prey relationship mice feed on grain and grain feeds on a resource with optimizing behavior of individual organisms a short run ecosystem equilibrium is defined and characterized that depends on the farmer s use of fertilizer and pesticide and on the mice population which in turn is affected by pesticides in that way a microfounded agricultural production function is derived linking a sequence of short run ecosystem equilibria yields the growth function of the mice population which is thus derived rather than assumed in each period the farmer harvests all grain in excess of some given amount of seed if she maximizes her present value profits optimal farming is characterized by either using no pesticide or a moderate amount of pesticide or by applying a chattering control pest eradication is never optimal on the other hand if the farmer takes into account steady state mice populations only it may be optimal to eradicate mice or to use no or a moderate amount of pesticide depending on prices as well as on the shape of the grain production function which is determined by microparameters of grain reproduction

impulse balance in the newsvendor game abstract one striking behavioral phenomenon is the pull to center bias in the newsvendor game facing stochastic demand subjects tend to order quantities between the expected profit maximizing quantity and mean demand we show that the impulse balance equilibrium which is based on a simple ex post rationality principle along with an equilibrium condition predicts the pull to center bias and other more subtle observations in the laboratory newsvendor game

independent private value auctions bidder behaviour in first second and third price auctions with varying numbers of bidders the symmetric equilibrium of third price auctions is characterized it makes a number of contrasting predictions relative to firms and second price auctions bids exceed private values the marginal effects on bids of an increase in private values is greater than one increasing numbers of bidders reduces bids and risk aversion requires bidding below the risk neutral nash equilibrium in the experiment bidders do not always satisfy the point predictions of the theory however the game theoretic models correctly anticipate at least directionally the important effects of the price rule changes copyright 1993 by royal economic society

natural resource economics and conservation contributions of agricultural economics and agricultural economists research by agricultural economists on natural resources has been distinguished by an interdisciplinary emphasis and a dynamic perspective it has recognized technological and institutional constraints has been oriented toward solving concrete resource management and policy problems and has emphasized empirical and quantitative analysis agricultural economists have introduced methods for evaluating natural resource conservation efforts for predicting adoption of resource conservation technologies and for designing efficient and sustainable resource management policies they have identified ways of improving land management and preventing land degradation proposed reforms of institutions governing water allocation and water quality and introduced policies for balancing environmental and efficiency considerations in the management of pests biodiversity and livestock diseases their research has had substantial impacts on the formulation of resource conservation policies

modeling asymmetric competition the effects of the marketing actions of one brand can be distributed among its competitors market shares in a complex manner this paper presents and illustrates methods for modeling brand competition and brand strategies in markets where competitive effects can be differentially and asymmetrically distributed we discuss the empirical specification parameter estimation and competitive strategy implications of the models proposed price and advertising competition among eleven brands of an australian household product is used to illustrate the application of these procedures

using neoclassical consumer choice theory to produce a market map from purchase data this article presents a new model for estimating the spatial representation of objects and preference vectors from actual choice behavior of individuals or households it is based on neoclassical economic theory of consumer choice the model integrates both decisions of which good s to buy and the quantity of purchase overall preference is decomposed into price effects and intrinsic preference for the good a maximum likelihood method for estimating the model parameters is described and illustrated using choice data of ketchup brands collected by the use of electronic supermarket scanners

stationary concepts for experimental 2 x 2 games comment reinhard selten and thorsten chmura 2008 recently reported laboratory results for completely mixed 2 x 2 games used to compare nash equilibrium with four other stationary concepts quantal response equilibrium action sampling equilibrium payoff sampling equilibrium and impulse balance equilibrium we reanalyze their data correct some errors and find that nash clearly fits worst while the four other concepts perform about equally well we also report new analysis of other previous experiments that illustrate the importance of the loss aversion hardwired into impulse balance equilibrium when the other non nash concepts are augmented with loss aversion they outperform impulse balance equilibrium

a single ideal point model for market structure analysis computing unsegmented product maps from preference data by means of single ideal point models is commonly thought to be impossible because of indeterminacy problems the authors show that this math

market boundaries and product choice illustrating attraction and substitution effects what happens to the share of choices each item receives when the choice set boundaries are extended by adding a new item that is extremely good on one dimension but poor on the others first there is a substitution effect whereby the new item takes choice share mainly from similar items in the set second there is an attraction effect resulting in a general shift of preference toward the added item experimental studies show that choice patterns conflict with current theoretical and common sense ideas about the effect of added alternatives on choice

the contribution of genetic modification to changes in corn yield in the united states we use a large rich dataset compiled from results of university extension trials to estimate the contribution of genetic modification gm to changes in corn yield in the united states from timea to timeb through repeated experimental trials we obtain consistent estimates of the effect of these traits by using both the hausman taylor estimator and a comparison of fixed effects estimates analogous to the agronomic practice of comparing near isolines our results suggest that gm traits had a positive impact on yield but that gains associated with combining several gm traits in one hybrid are not necessarily additive

5 information impact and allocation rules in auctions with affiliated private values a laboratory study in affiliated private value auctions each bidder has perfect information regarding his her own value for the object at auction but higher values of the item for one bidder make higher values for other bidders more likely we report on a series of experiments examining three key implications of these auctions i in a first price auction public information about rivals values increases expected revenue ii an english auction increases expected revenue compared to a first price auction and iii a second price auction is isomorphic to an english auction in examining these issues we compare predictions of some ad hoc bidding models with nash equilibrium predictions in the first price auction experiments nash equilibrium bidding theory organizes the data better than either of two ad hoc bidding models public information about others valuations does increase average revenue but the increase in revenue is smaller and less reliable than predicted under risk neutral nash equilibrium bidding lower average revenue might be attributed to risk aversion while the high variability is attributed to a sizable frequency of individual bidding errors relative to the theory bidding theory precisely organizes english auction outcomes after a brief initial learning period the dominant strategy equilibrium does not organize second price auctions nearly as well as market prices persistently exceed predicted prices the difference between english and second price outcomes is attributed to effects of different information flows inherent in the structure of the two institutions on eliminating bidding errors revenue impacts of these two institutions relative to a first price auction are examined in light of observed bidding patterns

bounded rationality models tasks to become intellectually competitive abstract research in experimental economics has cogently challenged the fundamental precept of neoclassical economics that economic agents optimize the last two decades have seen elaboration of boundedly rational models that try to move away from the optimization approach in ways consistent with experimental findings nonetheless the collection of alternative models has made little headway supplanting the dominant paradigm we delineate key ways in which neoclassical microeconomics holds continuing and compelling advantages over bounded rationality models and suggest via a few examples the sorts of further difficult pushes that would be needed to redress this state of affairs closer collaboration between theoretic modeling and experiments is clearly seen to be necessary jel b40 c72 c90 d01 d21

choice map inferring a product market map from panel data this paper describes choice map a model that infers a product market map from panel data choice map is a stochastic brand choice model a random utility quantal choice model and a multidimensional scaling procedure choice map combines the parsimony of stochastic choice models the rationale of random utility models and the ability of multidimensional scaling procedures to simultaneously infer both brand positions and consumer preferences from preference choice data choice map assumes that consumers have stationary purchase probabilities for the observational period which makes the model best suited to frequently bought mature product categories neither experimental nor survey data are required traditional mapping methods that scale such data may not yield the same structure for low involvement products as will a procedure like choice map that scales behavioral data choice map s descriptive and predictive validity exceeds that of an alternative stochastic brand choice model the dirichlet multinomial for a test data set

nash equilibrium and the history of economic theory john nash s formulation of noncooperative game theory was one of the great breakthroughs in the history of social science nash s work in this area is reviewed in its historical context to better understand how the fundamental ideas of noncooperative game theory were developed and how they changed the course of economic theory

fifteen years of bt cotton in china the economic impact and its dynamics summary even though the economic benefit of bt cotton adoption in the short run has been well documented the dynamics of this benefit remain unclear in particular the possibility of pest resistance build up and secondary pest outbreaks has caused concern regarding the sustainability of this economic benefit in the long run hence this study analyzes the economic impact of bt cotton and its dynamics in china using nationally representative long panel data for 1997 2012 we show that this economic benefit continues 15 years after the commercialization of bt cotton

factors influencing the profitability of fertilizer use on maize in zambia major findings the additional maize produced from a given amount of fertilizer applied varied widely across households even after largely controlling for soil and rainfall conditions the median estimated response rate was 15 9kgs of maize per kg nitrogen applied under the range of conditions and smallholder management practices average maizefertilizer response rates declined as the application rate increased beyond 2 bags of urea and 2 bags of d compound factors raising the response rate and profitability of fertilizer use included timely availability application rates less than the moa 4x4 recommendation use of animal draft power in land preparation and use of hybrid seed in remote areas and given current management practices fertilizer use appears to be profitable only for a minority of smallholder farmers in the relatively remote areas for farmers in the more accessible areas profitability of fertilizer use depends on timely availability if fertilizer is not available on time even farmers in the more accessible parts of this area of relatively high agronomic suitability for maize production are largely unable to use fertilizer profitably because over 30 percent of the households reported that fertilizer was delivered late these findings indicate that efforts to ensure timely distribution can contribute substantially to the productivity gains achievable from fertilizer use

features of experimentally observed bounded rationality abstract on the basis of experimental evidence reported in the literature the paper draws conclusions about the bounded rationality exhibited by human economic behaviour among the topics discussed are presentation effects caused by superficial analysis strategic reasoning and strategy construction based on reciprocity and fairness avoidance of circular concepts in step by step strategic reasoning ex post rationality and learning direction theory presence of both adaptive and analytic approaches to repeated decision tasks and the absence of quantitative expectations and optimization in typical repeated game strategies

smart policies to reduce pesticide use and avoid income trade offs an agent based model applied to thai agriculture abstract policy makers in developing countries need better evidence of how changes in pesticide regulation would affect pesticide reduction and farm incomes but there are very few modeling tools that can provide such information the present study develops a new model based on mathematical programming based multi agent system mpmas a simulation software that allows assessing ex ante the impact of alternative pesticide use reduction strategies including combinations of pesticide taxes the introduction of integrated pest management a price premium for safe agricultural produce and subsidies for biopesticides the model is parameterized with farm and plot level data from northern of thailand where the adoption of high value cash crops has been accompanied by a rapid increase in synthetic pesticide use simulation results suggest that a pesticide tax alone has little effect on synthetic pesticide use a smart policy package combining integrated pest management a progressive pesticide tax based on toxicity and subsidies lowering the price of biopesticides can reduce average use of hazardous pesticides by 34 over current levels without adverse effects on the average farm income

effective costs and chemical use in united states agricultural production using the environment as a free input a cost function based production model is used to represent patterns of input use and output production in u s agriculture and the implied costs of induced reductions in risk from agricultural chemicals bad outputs we estimate and evaluate shadow values for these harmful outputs and the implied input and output specific substitution patterns with a focus on the impacts on pesticide demand and its quality and quantity components using state level data we find these measures to be statistically significant vary substantively by region and imply increased demand for effective pesticides associated with improvements in quality from embodied technology copyright 2002 oxford university press

a new analytical framework for the fertilization problem a novel control model for technical and economic analysis of fertilizer recommendations is based on liebig s law of the minimum mitscherlich s relative yield theory and the notions of yield plateau and soil fertility carry over the empirical model consists of a multistage separable programming specification which maximizes the discounted stream of net revenues subject to crop response and fertility carry over functions the model is applied to the wheat soybean cropping system in southern brazil it is found that while the optimal fertility target levels are within a small range of those determined by brazilian agronomists their maintenance recommendations could be substantially improved control relative yield yield plateau the analysis of yield response to fertilizers has been recently enriched by an original proposal of cate and nelson these soil scientists suggested that for agronomic purposes and for certain crops it may be convenient to postulate that the relationship between yield and major nutrients is a linear response and plateau lrp function they argued that this simplified specification is nonetheless capable of capturing the essential information of yield

stationary concepts for experimental 2x2 games a reply this is a reply to stationary concepts for experimental 2 x 2 games comment by brunner camerer and goeree which corrects some computational errors in selten and chmura 2008 and extends the comparison of five stationary concepts to data from previous experimental studies we critically discuss their new findings and relate them to the data of selten and chmura 2008 we conclude that the parametric concepts of action sampling equilibrium and payoff sampling equilibrium perform better than quantal response equilibrium and that the non parametric concept of impulse balance equilibrium performs at least as well as quantal response equilibrium

simple econometrics of pesticide productivity this paper develops a multioutput generalization of the lichtenberg zilberman damage control technology the dual representation of the technology is shown to be conditionally additive in the price of abatement activities and other prices an econometric procedure for estimating the dual technology is developed and applied to an aggregate u s agricultural data set the conditionally additive nature of the model allows estimation of pest damage from the dual technology our estimates of aggregate u s pest damage are much lower than previous estimates

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

sub therapeutic antibiotics and the efficiency of u s hog farms antimicrobial drugs are frequently fed to hogs at sub therapeutic levels to promote feed efficiency and growth however in response to concerns that sub therapeutic antibiotics stas are promoting the development of antimicrobial drug resistant bacteria the u s food and drug administration recently adopted a strategy to phase out antibiotics for such production uses this study uses a stochastic frontier model to estimate the costs to u s hog producers of a ban on stas for growth promotion to address potential sample selection issues we employ a recently developed empirical approach that corrects for biases from both observed and unobserved variables

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

determining the appropriate depth and breadth of a firm s product portfolio abstract some firms have broad product lines others have lean product lines to determine the appropriate number of entries in a specific firm s product line the author develops a model that balances the benefits of increased revenue from a broad product line against production and engineering costs two innovations were central in the development of the model 1 redefining how products are scored on various product attributes so that attribute scores vary normally across the population of products and 2 redefining how the number of entries in a product portfolio is calculated in order to discount the significance of entries that are highly similar to existing products the author also introduces the notion of a centroid time to more easily adjust sales and total development costs for product life cycle and investment life cycle effects these redefinitions enable a firm s profit to be modeled as a simple function of its effective number of product entries the effective number of competitors entrie

economic returns to crop management research in a post green revolution setting returns to research studies have neglected research on crop management cmr which may account for half of all crop research because cmr enhances the efficiency of input use returns to cmr are hypothesized to increase in settings characterized by high input levels and high yields a method is developed to estimate returns to cmr and this method is applied to wheat research in a post green revolution setting in northwest mexico the results suggest that returns to cmr are positive over a range of model assumptions

private eradication of mobile public bads we consider analytically the non cooperative behavior of many private property owners who each controls the stock of a public bad such as an invasive weed species infectious disease fire or agricultural pest the stock of the public bad can grow and disperse across a spatial domain of arbitrary size in this setting we characterize the conditions under which private property owners will control or eradicate and determine how this decision depends on property specific environmental features and on the behavior of other landowners we show that high mobility or lower control by others result in lower private control but when the marginal dynamic cost of the bad is sufficiently large we find that complete eradication may be privately optimal despite the lack of consideration of others welfare in these cases eradication arises in the non cooperative game and is also socially optimal so there is in effect no externality finally when property harboring the bad is not owned or is owned in common we derive the side payments required to efficiently control the mobile public bad

integrating agronomic principles into production function specification a dichotomy of growth inputs and facilitating inputs this article presents a general conceptual framework for integrating agronomic principles into economic production analysis we categorize inputs in crop production into growth inputs and facilitating inputs based on this dichotomy we specify an asymmetric production function the robustness of the asymmetric framework is tested using crop level panel data on potato production in the netherlands the test results do not reject the proposed framework and the asymmetric specification better represents the underlying production technology

damage control and increasing returns the indirect action of damage control inputs means the marginal productivity of these inputs depends on their effectiveness in controlling the level and size of production loss caused by the damage agent increasing returns to damage control inputs can occur even when control and damage functions are concave the result implies more attention needs to be paid to the functional form selection for damage and control functions in empirical work on pest control and other types of damage control inputs in addition the possibility of increasing returns may undermine the general use of taxes to reduce pesticide use

choosing children s environmental risk a model of endogenous risk provides a foundation to study a parent s child care decisions when the child could be exposed to an environmental hazard e g toxic substance foodborne pathogen the parent invests in childcare quality and quantity to reduce the likelihood of a hazard exposure occurring and to reduce its severity if the exposure is realized we supply conditions to sign unambiguously the effects on a child s hazard exposure of an increased probability a parent fails to access or have command over a technique of exposure prevention or that a technique is ineffective in preventing exposure also we consider these effects when the parent is unsure what a technique can do to reduce the child s probability of exposure we conclude public policies designed to encourage use of a particular childcare technique if childcare quality and quantity are stochastic substitutes can reduce parental use of other techniques the net impact of the policy could increase the chance the child suffers

testing competitive market structures an accurate understanding of the structure of competition is important in the formulation of many marketing strategies for example in new product launch product reformulation or positioning decisions the strategist wants to know which of his competitors will be most affected and hence most likely to respond many marketing science models have been proposed to identify market structure in this paper we examine the managerial problem and propose a criterion by which to judge an identified market structure basically our criterion is a quantification of the intuitive managerial criterion that a submarket is a useful conceptualization if it identifies which products are most likely to be affected by our marketing strategies we formalize this criterion within the structure of classical hypothesis testing so that a marketing scientist can use statistical statements to evaluate a market structure identified by 1 behavioral hypotheses 2 managerial intuition or 3 market structure identification algorithms mathematically our criterion is based on probabilities of switching to products in the situation where an individual s most preferred product is not available submarkets are said to exist when consumers are statistically more likely to buy again in that submarket than would be predicted based on an aggregate constant ratio model for example product attributes e g brand form size use situations e g coffee in the morning versus coffee at dinner and user characteristics e g heavy versus light users are specified as hypotheses for testing alternate competitive structures measurement and estimation procedures are described and a convergent approach is illustrated an application of the methodology to the coffee market is presented and managerial implications of six other applications are described briefly

pests and pesticides risk and risk aversion abstract theoretical and applied literature on risk in decision making for agricultural pest control is reviewed risk can affect pesticide decision making either because of risk aversion or because of its influence on expected profit it is concluded that risk does not necessarily lead to increased pesticide use by individual farmers uncertainty about some variables such as pest density and pest mortality does lead to higher optimal pesticide use under risk aversion however uncertainty about other important variables such as output price and yield leads to lower optimal levels of pesticide use neglect of these variables in most studies has led to the false assumption that pesticides are always risk reducing inputs furthermore there is evidence that in general the pesticide dosage which maximises expected profit is lower under risk than under certainty depending on the balance of forces to increase and decrease pesticide use under risk in many circumstances the net effect of risk on optimal decision making for pest control may be minimal the effect on risk of information about pest density and other variables as in integrated pest management programmes is discussed evidence on this issue is mixed a range of analytical techniques for analysing risk in pest control is reviewed throughout the paper gaps in the existing literature are identified

another look at pesticide productivity and pest damage using the lichtenberg zilberman fox weersink damage specification we develop a short run supply response framework based on rational producer behavior in the presence of damage agents we show how representation can be used to measure and decompose the economic damage associated with the presence of pests how to measure the shadow prices of damage control agents how to measure the manner in which pesticide application biases variable input use and how pesticide application affects the relative returns to quasi fixed factors of production an econometric version of the model is estimated using a panel data set on greek olive producers both our theoretical and our empirical results suggest that the most traditional measure of pest damage understates actual economic losses and revenue losses due to pests

nonspeculative bubbles in experimental asset markets lack of common knowledge of rationality vs actual irrationality we report the results of an experiment designed to study the role of speculation in the formation of bubbles and crashes in laboratory asset markets in a setting in which speculation is not possible bubbles and crashes are observed the results suggest that the departures from fundamental values are not caused by the lack of common knowledge of rationality leading to speculation but rather by behavior that itself exhibits elements of irrationality much of the trading activity that accompanies bubble formation in markets where speculation is possible is due to the fact that there is no other activity available for participants in the experiment

the economic threshold with a stochastic pest population a real options approach using real options this paper formulates an optimal stopping model for applying pest control measures when the density of a pest population varies randomly a delay between successive pesticide applications is introduced to analyze the farmer s expected marginal cost of reentry this model is applied to the control of a foliar pest of apples via a pesticide and solved numerically a sensitivity analysis shows that the pest density that should trigger pesticide use can vary significantly with the pest density volatility incorporating pest randomness into simple decision rules may thus help better manage the chemicals applied to soils and crops

reforming intellectual property rights and the bt cotton seed industry in china who benefits from policy reform china has been one of the leaders in agricultural biotechnology research and the adoption of transgenic plants despite this critics argue that china s biotechnology policies could be improved to provide more benefits to farmers the objective of the paper is to examine if policy changes could improve the welfare of farmers in the cotton industry the paper first reviews recent changes in laws and policies that affect china s plant biotechnology sector with a focus on ipr legislation and seed industry reform next using a primary data set collected from 1661 plots from a sample of farmers in northern china in 1999 2000 we econometrically estimate the effect of changes to intellectual property rights ipr and seed and 2001 industry reform on farmer pesticide use and yields our results are consistent with a conclusion that improvements to the ipr environment and greater commercialization of the seed industry can increase the benefits that farmers derive from new cotton technology c 2008 elsevier b v all rights reserved

the econometrics of damage control lichtenberg and zilberman argue correctly that when biological and physical processes are considered we are able to delineate two components of actual realized crop yields potential output the maximum quantity of product obtainable from any given combination of inputs and losses caused by damaging agents present in the environment p 262 they further argue that damage control agents should be defined in terms of their contribution to the abatement effort and hence should enter the production function as an argument of the damage abatement function to demonstrate the consequences of their claims lichtenberg and zilberman make an ad hoc choice of a cobb douglas functional form for crop yield exogenous factors such as pest prevalence and weather conditions are ignored although they note that omission of these environmental factors will result in misspecification of the production relationship p 267

the economics of biotechnology under ecosystem disruption abstract economic analysis of chemical pesticide use has shown that the interactions between plants pests damage control technology and state of the ecosystem are important variables to be considered hence a bio economic model was developed for the assessment of bt variety and pesticide based control strategies of the cotton bollworm in china the model simulates plant growth the dynamics of pest populations and of natural enemies the model predictions are used as major inputs for a stochastic micro level profit model of alternative control strategies results show that 1 productivity effects of bt varieties and pesticide use depend on the action of natural control agents and 2 the profitability of damage control measures increases with the severity of ecosystem disruption the findings highlight the importance of the choice of the counterfactual scenario in the assessment of the impact of agricultural biotechnology also some doubts are raised whether the high benefits of bt cotton varieties claimed by previous studies based on cross section comparisons are realistic

a nonparametric density estimation method for brand choice using scanner data nonparametric density estimation using a kernel method is proposed to model consumer brand choice recent availability of large scanner panel data allows the use of nonparametric approach which has few or at least fewer underlying assumptions and affords greater structural flexibility by removing as many assumptions as possible the author constructs the ultimate nonparametric model radically departing from the traditional approaches to highlight the differences in implementation and performance the proposed model does not involve either parameters that approximate certain distributions as in stochastic models or latent concepts such as utility as in utility maximization models the performance criteria include prediction of market response and brand choice share tracking and robustness under violation of various assumptions involved in parametric choice models such as correlated disturbance and misspecification the method is compared with a popular parametric counterpart the multinomial logit model on simulated and actual scanner panel data the paper emphasizes the conceptual importance of the nonparametric approach by discussing its advantages limitations and its complementary role in developing refining and diagnosing parametric models this perspective affords insight to modeling philosophy and suggests the possibility of a hybrid approach

bt cotton in india field trial results and economic projections abstract the performance of bt cotton in india is analyzed on the basis of field trial data from 2001 the amounts of pesticides applied during the trials were reduced to one third of what was used in conventional cotton while under severe pest pressure yield gains were 80 productivity effects are modeled econometrically with a damage control specification the first approval for the commercial cultivation of bt hybrids was given in 2002 by 2005 the technology is expected to cover one quarter of total indian cotton area medium term projections show sizeable welfare gains for the overall economy with farmers being the main beneficiaries

the economics and econometrics of damage control concern for the potentially harmful side effects of agricultural chemical inputs especially pesticides highlights the need to accurately determine the economic levels of their use we consider three model specification issues interaction of direct production inputs with damage control inputs in damage abatement justification for a priori exclusion of production inputs from the abatement function and the motivations and consequences of alternative stochastic specifications empirical analysis using farm level data shows that misspecification of the stochastic element in the production function can overestimate the marginal physical productivity of pesticides and grossly underestimate the responsiveness of demand to increases in pesticide prices

take a risk preferring prevention over control of biological invaders abstract scientists have argued that invasive species can be managed most cost effectively with greater investments in prevention further under ideas like the precautionary principle it is reasonable to expect that a cautious manager would use more prevention relative to control because it keeps more invaders out yet this is not typically done in many cases private and public resources are invested primarily to control existing invaders rather than to prevent new invasions managers frequently wait until after invaders have arrived and then scramble to limit the damages we believe these paradoxical decisions can be understood by recognizing the link between typical human preferences for risk bearing and the technology of risk reduction we demonstrate quantitatively how managers perceived to be cautious or averse to risk tend to shy away from prevention relative to control this counterintuitive result arises because control is a safer choice than prevention because its productivity is relatively less risky it works to remove existing invaders from the system in contrast the productivity of prevention is more uncertain because prevention only reduces the chance of invasion it does not eliminate it and invasion may not occur even in the absence of prevention managers averse to risk will inherently avoid as much uncertainty as possible whether the source of uncertainty regards ecological outcomes or economic productivity implications for environmental decision making are clear in invasive species management if managers act as though they are risk averse their caution can backfire when it leads to more control rather than prevention the social consequences of this choice are a greater probability of future invasions and lower social welfare our results suggest that social welfare is highest when managers were willing to take a risk with prevention

production risk pesticide use and gm crop technology in south africa technology involving genetic modification of crops has the potential to make a contribution to rural poverty reduction in many developing countries thus far pesticide producing bacillus thuringensis bt varieties of cotton have been the main gm crops under cultivation in developing nations several studies have evaluated the farm level performance of bt varieties in comparison to conventional ones by estimating production technology and have mostly found bt technology to be very successful in raising output and or reducing pesticide input however the production risk properties of this technology have not been studied although they are likely to be important to risk averse smallholders this study investigates the output risk aspects of bt technology by estimating two flexible risk production function models allowing technology to independently affect the mean and higher moments of output the first is the popular just pope model and the second is a more general damage control flexible risk mode

pesticides productivity and farmer health a philippine case study health is recognized as one of the most important components of the human capital of rural people in developing countries there is a growing body of literature showing the productivity effects of health associated with nutrition e g bliss and stern 1978 strauss 1986 deolalikar 1988 pitt rosenzweig and hassan 1990 in this literature the productivity effects of health are inferred either by correlating health indicators with wages or by including health indicators in an agricultural production function the human capital literature also has demonstrated that farmer education plays an important role in the allocative and technical efficiency of farmers welch 1970 schultz 1975

impulse balance equilibrium and feedback in first price auctions abstract experimental sealed bid first price auctions with private values in which feedback on the losing bids is provided yield lower revenues than auctions where this feedback is not given the concept of weighted impulse balance equilibrium which is based on a principle of ex post rationality and incorporates a concern for social comparison captures the data

taking one for the team is collective action more responsive to ecological change debate persists around the timing of risk reduction strategies for large scale ecological change for three reasons risks are difficult to predict they involve irreversibilities and they impact multiple jurisdictions the combination of these three factors creates a general class of filterable spatial dynamic externalities fsde in which one person s risk reduction investments reduce or filter undesirable events experienced by others and underestimates the option value placed on being able to respond to new information about the consequences of ecological change by focusing on the optimal intervention decision we illustrate how and when the opposing forces created by an fsde will lead to a divergence in private and collective risk reduction strategies we use bioinvasions as our motivating example the bioinvasion first hits one jurisdiction and that jurisdiction s risk reduction investment reduces the risk faced by all other jurisdiction we find that efforts to internalize the full benefits of risk reduction investments may have unintended consequences on the responsiveness of environmental policy there is a social welfare gain from asking the first jurisdiction to delay a risk reduction investment to internalize the option values of all at risk jurisdictions

finite bubbles with short sale constraints and asymmetric information abstract we present a finite period general equilibrium model of an exchange economy with asymmetric information we say that a rational expectations equilibrium exhibits a strong bubble if the price is higher than the dividend with probability one we show that necessary conditions for a strong bubble to occur are that 1 each agent must have private information in the period and state in which the bubble occurs 2 each agent must be short sale constrained at some period in the future with positive probability and 3 agents trades are not common knowledge we present examples of bubbles when the necessary conditions are satisfied journal of economic literature classification numbers c72 d52 d82 d84 g12 g14

predictive testing of consumer choice models not subject to independence of irrelevant alternatives the probabilistic modeling of the relationship between objective or perceived characteristics of multiattribute alternatives and consumer choice is receiving increased attention in marketing and ot

using discrete choice models with experimental design data to forecast consumer demand for a unique cultural event an approach is developed to forecast participation in unique events with long gestation periods experimental observations of choice are derived for conjoint measurement type multiattribute alternatives that describe possible event configurations the choice data are analyzed by means of discrete choice econometric models a multinomial logit choice model is applied to forecast the choice of attendance at various types of international expositions the empirical work was part of the planning efforts undertaken to investigate the potential demand for an international exposition to be held in eastern australia in conjunction with the australian 1988 bicentennial celebrations

damage control econometrics functional specification and pesticide productivity empirical studies of pesticide productivity have often concluded that the value of marginal product of pesticide exceeds marginal factor cost despite anecdotal and other evidence to the contrary this article presents estimates of pesticide productivity derived from alternative functional specifications of pesticide involvement in production results suggest that explanation of the magnitude of pesticide productivity estimates obtained in empirical studies may lie somewhere other than with functional specification

rationalizability learning and equilibrium in games with strategic complementarities we study a rich class of noncooperative games that includes models of oligopoly competition macroeconomic coordination failures arms races bank runs technology adoption and diffusion r d competition pretrial bargaining coordination in teams and many others for all these games the sets of pure strategy nash equilibria correlated equilibria and rationalizable strategies have identical bounds also for a class of models of dynamic adaptive choice behavior that encompasses both best response dynamics and bayesian learning the players choices lie eventually within the same bounds these bounds are shown to vary monotonically with certain exogenous parameters we study the class of noncooperative supermodular games introduced by topkis 1979 and further analyzed by vives 1985 1989 who also pointed out the importance of these games in industrial economics supermodular games are games in which each player s strategy set is partially ordered the marginal returns to increasing one s strategy rise with increases in the competitors strategies so that the game exhibits strategic complementarity 2 and if a player s strategies are multidimensional marginal returns to any one com ponent of the player s strategy rise with increases in the other components this class turns out to encompass many of the most important economic applications of noncooperative game theory in macroeconomics diamond s 1982 search model and bryant s 1983 1984 rational expectations models can be represented as supermodular games in each of these models more activity by some members of the economy raises the returns to increased levels of activity by others in oligopoly theory some models of bertrand oligopoly with differentiated products qualify as supermodu lar games in these games when a firm s competitors raise their prices the marginal profitability of the firm s own price increase rises a similar structure is present in games of new technology adoption such as those of dybvig and spatt 1983 farrell and saloner 1986 and katz and shapiro 1986 when more users hook into a communication system or more manufacturers adopt an interface standard the marginal return to others of doing the same often rises similarly in some specifications of the bank runs model introduced by diamond and dybvig 1983 when more depositors withdraw their funds from a bank it is more worthwhile for other depositors to do the same in the warrant exercise

the importance of seasonal variability and tactical responses to risk on estimating the economic benefits of integrated weed management seasonal variability is an important source of risk faced by farmers and regardless of an individual s attitude to risk there are options to tactically adjust production strategies as the outcomes of risk become known the objective of this article is to measure the economic benefits of alternative approaches to managing weeds one of the most serious production problems in australian cropping systems a bioeconomic model that combines weed biology crop growth and economics is developed to value the effects of seasonal variability and the role of tactical responses and sequential decision making in determining an optimal integrated weed management strategy this shows that there are substantial differences in the measured long term benefits from deterministic and stochastic simulations it is concluded that for research evaluation of technologies that involve complex biological and dynamic systems ignoring the impacts of seasonal variability responses to risk and sequential decision making can lead to an incorrect estimate of the economic benefits of a technology in this case study of optimal weed management strategies in australia the size of the error is high

firm organizational heterogeneity and market structure evidence from the japanese pesticide market abstract this paper empirically investigates the effects of the organizational forms of firms on their entry behaviors and market structure to exploit the exogenous variation in firm organizational forms we use japanese pesticide market data first our empirical analysis shows that a model of imperfect competition fits the japanese pesticide market well despite the existence of regulations we then estimate the effect of organizational heterogeneity on entry behavior firms having capital ties with special distribution networks tend to enter this market more readily than do firms without such ties furthermore diversified and vertically nonintegrated firms are more likely to enter this market than are stand alone and vertically integrated firms these findings suggest that markets with distribution related diversified and vertically nonintegrated potential entrants are more competitive than those with the same number of potential entrants that have no such characteristics

stationary concepts for experimental 2x2 games five stationary concepts for completely mixed 2 x 2 games are experimentally compared nash equilibrium quantal response equilibrium action sampling equilibrium payoff sampling equilibrium martin j osborne and ariel rubinstein 1998 and impulse balance equilibrium experiments on 12 games 6 constant sum games and 6 nonconstant sum games were run with 12 independent subject groups for each constant sum game and 6 independent subject groups for each nonconstant sum game each independent subject group consisted of four players 1 and four players 2 interacting anonymously over 200 periods with random matching the comparison of the five theories shows that the order of performance from best to worst is as follows impulse balance equilibrium payoff sampling equilibrium action sampling equilibrium quantal response equilibrium nash equilibrium