pricing of electricity tariffs in competitive markets in many countries electricity supply business has been opened for competition in this paper we analyze the problem of pricing of electricity tariffs in these open markets when both the customers electricity consumption and the market price are stochastic processes specifically we focus on regular tariff contracts which do not have explicit amounts of consumption units defined in the contracts therefore the valuation process of these contracts differs from the valuation of electricity futures and options the results show that the more there is uncertainty about the customer s consumption the higher the fixed charge of the tariff contract should be finally we analyze the indication of our results to the different methods for estimating the customer s consumption in the competitive markets since the consumption uncertainties enter into the tariff prices the analysis indicates that the deterministic standard load curves do not provide efficient methods for evaluating the customers consumption in competitive markets

evolution in games with randomly disturbed payoffs we consider a simple model of stochastic evolution in population games in our model each agent occasionally receives opportunities to update his choice of strategy when such an opportunity arises the agent selects a strategy that is currently optimal but only after his payoffs have been randomly perturbed we prove that the resulting evolutionary process converges to approximate nash equilibrium in both the medium run and the long run in three general classes of population games stable games potential games and supermodular games we conclude by contrasting the evolutionary process studied here with stochastic fictitious play

taking stock a rigorous modelling of animal spirits in macroeconomics modelling animal spirits this paper is a survey of the burgeoning literature that seeks to take the enigmatic concept of the animal spirits more seriously by building heterodox macro dynamic models that can capture some of its crucial aspects in a rigorous way two approaches are considered the discrete choice and the transition probability approach where individual agents face a binary decision and choose one of them with a certain probability these assessments are adjusted upward or downward in response to what the agents observe which leads to changes in the aggregate sentiment and the macroeconomic variables resulting from the corresponding decisions typical applications of the two approaches alternatively give rise to what will be called a weak and a strong form of animal spirits on the whole the literature included in this survey provides examples of applications of a modelling tool that demonstrates a considerable flexibility within a canonical framework

adjustment dynamics and rational play in games when a given strategic situation arises repeatedly the possibility arises that equilibrium predictions can be justified by a dynamic adjustment process we examine myopic adjustment dynamics a class that includes replicator dynamics from evolutionary game theory simple models of imitation models of experimentation and adjustment and some simple learning dynamics we present a series of theorems showing conditions under which behavior that is asymptotically stable under some such dynamic is strategically stable in the sense of kohlberg and mertens this behavior is thus as if the agents in the economy satisfied the extremely stringent assumptions that game theory traditionally makes about rationality and beliefs journal of economic literature classification number c72

the war of attrition in continuous time with complete information this paper provides a complete characterization of the nash equilibrium outcomes for the war of attrition when time is continuous and information is complete it allows for asymmetric payoffs and an arbitrary time horizon in addition to certain asymme tric pure strategy equilibria that always exist the authors establi sh the conditions under which there is also a continuum of mixed strategy equilibria these are most likely to exist when either the horizon is infinite or the game is symmetric copyright 1988 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

the case for permissive patents whatever its shortcomings in practice until very recently patent law has sought to embody the winner takes all principle this paper argues that it is both feasible and desirable to allow multiple prizes indeed it is possible that complete abolition of the patent system by raising the returns to late finishers would yield an improvement on the current situation

the projection dynamic and the geometry of population games abstract the projection dynamic is an evolutionary dynamic for population games it is derived from a model of individual choice in which agents abandon their current strategies at rates inversely proportional to the strategies current levels of use the dynamic admits a simple geometric definition its rest points coincide with the nash equilibria of the underlying game and it converges globally to nash equilibrium in potential games and in stable games

on the winner take all principle in innovation races what is the optimal allocation of prizes in an innovation race should the winner take all or is it preferable that the original inventor shares the market with subsequent independent duplicators some recent papers in law and economics have argued that the latter more permissive solution is socially preferable under mild conditions we re examine that issue arguing that a permissive regime may turn the innovation race into a waiting game reducing the power of incentives and may invite socially wasteful duplicative r d expenditures in a model that accounts for these effects the winner take all system turns out to be preferable in a broad set of circumstances especially in highly innovative industries jel k11 l1 o34

a note on best response dynamics we investigate the relationship between the continuous time best response dynamic its perturbed version and evolutionary dynamics in relation to mixed strategy equilibria we find that as the level of noise approaches zero the perturbed best response dynamic has the same qualitative properties as a broad class of evolutionary dynamics that is stability properties of equilibria are robust across learning dynamics of quite different origins and motivations journal of economic literature classification numbers c72 d83

free entry and social inefficiency our goal is to provide a simple yet general exposition of the conditions under which the number of entrants in a free entry equilibrium is excessive insufficient or optimal our analysis compares the number of firms that enter a market when there is free entry with the number that would be desired by a social planner who is unable to control the behavior of firms once they are in the market that is we consider the second best problem of choosing the welfare maximizing number of firms while we take as given their noncompetitive behavior after entry we demonstrate that the crucial conditions for establishing the presence of an entry bias can be stated quite simply in terms of the outcome of the postentry game played by entrants in contrast to previous work we do not need to model this postentry game explicitly

patents and the global diffusion of new drugs analysis of the timing of launches of 642 new drugs in 76 countries during 1983 2002 shows that patent and price regulation regimes strongly affect how quickly new drugs become commercially available in different countries price regulation delays launch while longer and more extensive patent rights accelerate it health policy institutions and economic and demographic factors that make markets more profitable also speed up diffusion the estimated effects are generally robust to controlling for endogeneity of policy regimes with country fixed effects and instrumental variables the results highlight the important role of policy choices in driving the diffusion of new innovations

irreversible investment and r d spillovers in a dynamic duopoly investments in new production processes usually involve a significant amount of rd an increase in uncertainty delaying the equilibrium calls for higher subsidization rates third numerical simulations show that the spillover reduces the difference between the leader s and the follower s maximum value functions accordingly our model can help generate realistic market betas

excess payoff dynamics and other well behaved evolutionary dynamics abstract we consider a model of evolution in games in which agents occasionally receive opportunities to switch strategies choosing between them using a probabilistic rule both the rate at which revision opportunities arrive and the probabilities with which each strategy is chosen are functions of current normalized payoffs we call the aggregate dynamics induced by this model excess payoff dynamics we show that every excess payoff dynamic is well behaved regardless of the underlying game each excess payoff dynamic admits unique solution trajectories that vary continuously with the initial state identifies rest points with nash equilibria and respects a basic payoff monotonicity property we show how excess payoff dynamics can be used to construct well behaved modifications of imitative dynamics and relate them to two other well behaved dynamics based on projections

evolutionary implementation and congestion pricing we consider an implementation problem faced by a planner who manages a roadway network the problem entails both hidden information and hidden actions we solve the planner s problem by introducing a new class of mechanisms and a new notion of implementation the mechanisms called price schemes attach transfers to the available routes they do not involve direct revelation the method of implementation is evolutionary requiring that players who follow any reasonable myopic adjustment process eventually learn to behave as the planner desires we show that efficient behaviour can be guaranteed using simple decentralized price schemes

bidding in sequential electricity markets the nordic case abstract for electricity market participants trading in sequential markets with differences in price levels and risk exposure it is relevant to analyze the potential of coordinated bidding we consider a nordic power producer who engages in the day ahead spot market and the hour ahead balancing market in both markets clearing prices and dispatched volumes are unknown at the time of bidding however in the balancing market the market participant faces an additional risk of not being dispatched taking into account the sequential clearing of these markets and the gradual realization of market prices we formulate the bidding problem as a multi stage stochastic program we investigate whether higher risk exposure may cause hesitation to bid into the balancing market furthermore we quantify the gain from coordinated bidding and by deriving bounds on this gain assess the performance of alternative bidding strategies used in practice

runner up patents is monopoly inevitable exclusive patents sacrifice product competition to provide firms incentives to innovate we characterize an alternative mechanism whereby later inventors are allowed to share the patent if they discover within a certain time period of the first inventor these runner up patents increase social welfare under very general conditions furthermore we show that the time window during which later inventors can share the patent should become a new policy tool at the disposal of the designer this instrument will be used in a socially optimal mix with the breadth and length of the patent and could allow sorting between more or less efficient firms

the case against patents evidence that they serve to increase innovation and productivity unless productivity is identifi ed with the number of patents awarded which as productivity is identifi ed with the number of patents awarded which as evidence shows has no correlation with measured productivity this disconnect is evidence shows has no correlation with measured productivity this disconnect is at the root of what is called the patent puzzle in spite of the enormous increase in at the root of what is called the patent puzzle in spite of the enormous increase in the number of patents and in the strength of their legal protection the us economy the number of patents and in the strength of their legal protection the us economy has seen neither a dramatic acceleration in the rate of technological progress nor a has seen neither a dramatic acceleration in the rate of technological progress nor a major increase in the levels of research and development expenditure major increase in the levels of research and development expenditure both theory and evidence suggest that while patents can have a partial equiboth theory and evidence suggest that while patents can have a partial equilibrium effect of improving incentives to invent the general equilibrium effect on librium effect of improving incentives to invent the general equilibrium effect on innovation can be negative the historical and international evidence suggests that innovation can be negative the historical and international evidence suggests that while weak patent systems may mildly increase innovation with limited side effects while weak patent systems may mildly increase innovation with limited side effects strong patent systems retard innovation with many negative side effects more generstrong patent systems retard innovation with many negative side effects more generally the initial eruption of innovations leading to the creation of a new industry from ally the initial eruption of innovations leading to the creation of a new industry from chemicals to cars from radio and television to personal computers and investment chemicals to cars from radio and television to personal computers and investment banking is seldom if ever born out of patent protection and is instead the fruit of a banking is seldom if ever born out of patent protection and is instead the fruit of a competitive environment it is only after the initial stage of rampant growth ends that competitive environment it is only after the initial stage of rampant growth ends that mature industries turn toward the legal protection of patents usually because their mature industries turn toward the legal protection of patents usually because their internal growth potential diminishes and they become more concentrated these internal growth potential diminishes and they become more concentrated these observations supported by a steadily increasing body of evidence are consistent with observations supported by a steadily increasing body of evidence are consistent with

social stability and equilibrium in the field of noncooperative game theory nash equilibrium nash 1951 has played a central role as a solution concept in bold strokes one may discern two major interpretations of nash equilibrium in the context of rational players the first which is close to the eductive interpretation of binmore 1987 1988 and the complete information interpretation of kaneko 1987 assumes that the game is played exactly once if it is a repeated game the repetition occurs once and the players have sufficient knowledge and ability to analyze the game in a rational manner sometimes it is assumed that all players have consistent hierarchies of beliefs where the game and their priors are common knowledge bayesian interpretation such as proposed by aumann 1987 advanced this idea to the level that the players have a common prior from this point of view however nash equilibrium seems far from being satisfactory

offer stack optimization in electricity pool markets we consider a generator making offers of energy into an electricity pool market for a given time period it must submit an offer stack consisting of a fixed number of quantities of energy and prices at which it wants these quantities dispatched we assume that the generator cannot offer enough power to substantially affect the market price so the optimal response would be to offer energy at marginal cost however the market rules do not permit an arbitrary function so the problem is to find an offer stack approximating marginal cost in a way that maximizes its profit we give optimality conditions for this problem and derive an optimization procedure based on dynamic programming this procedure is illustrated by applying it to several examples with different costs of production

taking stock a rigorous modelling of animal spirits in macroeconomics this paper is a survey of the burgeoning literature that seeks to take the enigmatic concept of the animal spirits more seriously by building heterodox macro dynamic models that can capture some of its crucial aspects in a rigorous way two approaches are considered the discrete choice and the transition probability approach where individual agents face a binary decision and choose one of them with a certain probability these assessments are adjusted upward or downward in response to what the agents observe which leads to changes in the aggregate sentiment and the macroeconomic variables resulting from the corresponding decisions typical applications of the two approaches alternatively give rise to what will be called a weak and a strong form of animal spirits on the whole the literature included in this survey provides examples of applications of a modelling tool that demonstrates a considerable flexibility within a canonical framework

market offering strategies for hydroelectric generators this paper considers the problem of offering electricity produced by a series of hydroelectric reservoirs to a pool type central market the market model is a simplified version of the new zealand wholesale electricity market with prices modelled by a first order markov process the demand for electricity is not explicitly modelled the hydroelectric generator is assumed to be unable to influence market prices i e to be a price taker we discuss the resulting stochastic dynamic program methods for its solution and the explicit optimal offer curves that it produces it is shown that the utility function is monotone increasing with respect to both reservoir level and current price however the optimal offer curves need not be monotone this is shown by example numerical results are provided

second mover advantages in the strategic adoption of new technology under uncertainty abstract this paper introduces technological uncertainty into a timing game of new technology adoption it is shown that the timing neither necessarily involves first mover advantages in precommitment equilibria reinganum review of economic studies xlviii 1981 395 405 nor rent equalization due to the threat of preemption fudenberg and tirole review of economic studies lii 1985 383 401 rather there may be second mover advantages because of informational spillovers furthermore the model predicts that the equilibrium payoffs will typically be discontinuous and non monotonic in the probability that the new technology is profitable a welfare analysis reveals several market failures and suggests that policy intervention should adequately depend on the nature of uncertainty and the rate of technological progress

infection and immunization a new class of evolutionary game dynamics abstract building upon a central paradigm of evolutionary game theory namely the invasion barrier we propose the new infection and immunization dynamics infimmdyn modelling a plausible adaptation process in a large population for general games this yields a novel refinement of the nash equilibrium concept based on dynamical arguments close in spirit to nash s original mass action idea in his ph d thesis for partnership games infimmdyn exhibits a better asymptotic behavior compared to other popular procedures like fictitious play and replicator dynamics we establish even support separation of infimmdyn in finite time which can never be achieved by any interior point method like those mentioned above in fact this property has not yet been established for any other evolutionary game dynamics

on the diffusion of new technology a game theoretic approach this paper is an attempt at a rigorous albeit not exceedingly general analysis of the diffusion of new technology in particular consider an industry composed of two firms each using the current best practice technology the firms are assumed to be operating at nash equilibrium output levels generating a market price given demand and profit allocations when a cost reducing innovation is announced each firm must determine when if ever to adopt it based in part upon the discounted cost of implementing the new technology and in part upon the behavior of the rival firm if either firm adopts before the other it can expect to make substantial profits at the expense of the other firm on the other hand the discounted sum of purchase price and adjustment costs may decline with the lengthening of the adjustment period as various quasi fixed factors become more easily variable therefore although waiting costs the firm more in terms of foregone profits it may save money on the cost of purchasing the new technology thus the firm must weigh the costs and benefits of delaying adoption as well as take account of its rival s strategic behavior

preemption and rent equalization in the adoption of new technology we study the adoption of a new technology to illustrate the effects of preemption in games of timing we show that the threat of preemption equalizes rents in a duopoly but that this result does not extend to the general oligopoly game if the gain to preemption is sufficiently small then the optimal symmetric outcome which involves late adoption is an equilibrium this contrasts with reinganum s result that in precommitment equilibria there must be diffusion we develop a new and richer formalism for modeling games of timing which permits a continuoustime representation of the limit of discrete time mixed strategy equilibria

dynamic competition and intellectual property rights in a model of product development we study innovation timing and socially optimal intellectual property rights iprs when firms facing market uncertainty invest strategically in product development if demand growth and volatility are high attrition occurs and iprs should ensure the cost of imitation attains a lower bound we identify if demand growth and volatility are low then provided that the private imitation incentive is socially excessive iprs should set the cost of imitation high enough to induce preemption and possibly winner take all preemption moreover the welfare achieved with optimal iprs is then greater with endogenous innovation than if firm roles are predetermined illustrating the importance of fostering dynamic competition in extensions we show how firms benefit from open standards takeovers have ambiguous welfare effects and simple licensing schemes are welfare improving

strategic capacity investment under uncertainty this article considers investment decisions within an uncertain dynamic and duopolistic framework each investment decision involves to determine the timing and the capacity level the simultaneous analysis of timing and capacity decisions extends work on entry deterrence accommodation to consider a timing delay element we find that when applying an entry deterrence policy the first investor or incumbent overinvests in capacity for two reasons first it delays the investment of the second investor or entrant second the entrant will invest in less capacity we also find that greater uncertainty makes entry deterrence more likely

strategic bidding for price taker hydroelectricity producers this paper introduces a stochastic programming model that integrates strategic bids or offers for electricity in quantities and prices in a deregulated electricity market the model is designed to maximize the profits of a producer of electricity who manages a series of power plants along a river the model is compared with a previously reported stochastic model where the bidding process is disregarded the superiority of the new model is empirically demonstrated on historical data

strategic technology switching under risk aversion and uncertainty abstract firms devising green investment strategies within a deregulated environment must take into account not only economic and technological uncertainty but also strategic interactions due to competition also further complicating green investment decisions is the fact that firms are likely to exhibit risk aversion since alternative energy technologies entail risk that cannot be diversified therefore we develop a utility based real options framework for pre emptive and non pre emptive competition in order to analyse how economic and technological uncertainty interact with risk aversion to impact the adoption of an existing technology in the light of uncertainty over the arrival of an improved version we confirm that greater risk aversion delays investment and show that technological uncertainty accelerates the follower s entry delays the entry of the pre emptive leader and intriguingly does not affect the non pre emptive leader s investment decision also we show how the relative loss in the leader s value due to the follower s entry is affected by economic and technological uncertainty as well as risk aversion and how the risk of pre emption under increasing economic uncertainty raises the value of direct investment in the new technology relative to stepwise investment

optimal bidding strategies for hydro electric producers a literature survey in a competitive environment with bid based markets power generation companies desire to develop bidding strategies that maximize their revenue in this paper we ask what approaches and methodologies have been used to model the bidding problem for hydro electric producers we present the problem s developments over time and through reviewing different variants of the problem progressively build to the case in which the agent is a price maker hydro electric producer in each variant of the bidding problem we examine how the approaches used to solve it may or may not be applicable to other variants last for the price maker hydro electric producer s bidding problem we recognize the most recent developments and illuminate a path for future efforts