climbing the hierarchical ladders of rules a life cycle theory of institutional evolution this paper proposes an analysis of the emergence and evolution of institutional frameworks it explains the causes process and outcome of institutional evolution we first describe the institutional framework as a multilevel system at the bottom of which several local and flexible institutions apply to subsets of the society while at the top a single generic and rigid institution applies to all dissatisfied with generic order promoters of local orders try to design collective governance solutions that are better suited to their needs if agents are heterogeneous as we assume then coordination needs differ and a competitive process begins among sponsors of alternative orders to benefit from efficiency gains promoters of local orders encourage adherence to their preferred system of rules the resulting competition for adherents explains why local and voluntary institutions might progressively turn into generic and mandatory ones we thus establish a logical continuum between contractual governance mechanisms and institutions we then analyze the strategic interplay among sponsors of alternative institutional orders by considering not only the horizontal competition among institutions emerging in the same time but also the vertical competition between promoters of new rules and sponsors of the established more generic rules

barriers and drivers in the adoption of advanced wastewater treatment technologies a comparative analysis of italian utilities abstract the adoption of new environmentally friendly technologies is becoming a key issue in both public debate and policy arenas the paper focuses on innovation adoption by wastewater utilities and investigates why stringent environmental regulations are not sufficient to foster it the adoption of advanced wastewater treatment technologies is made complex by the sunk nature of highly specific infrastructures and the consequent exposure of utilities to political and institutional influences in addition it requires the involvement of various actors utilities suppliers contractors and is influenced by various stakeholders communities business users citizens associations that generally have no aligned objectives with reference to the aforementioned theoretical background our paper develops and analyzes a conceptual framework that unfolds over two dimensions a the role played by firm specific characteristics i e technological and organizational capabilities and managerial professionalism b the influence of community level factors i e citizens voice and pressure exerted by local stakeholders we investigate these issues through multiple descriptive case studies based on semi structured interviews with the ceos and top managers of 11 wastewater utilities operating in a region in north italy the results suggest that firm specific resources could spur wastewater utilities into adopting innovation despite an adverse institutional environment at the same time on the community level side the analysis shows that residents and local businesses are able to mobilize resources and exert pressure to either drive or hinder the adoption of water innovations

the energy efficiency paradox revisited through a partial observability approach the present paper examines the energy efficiency paradox demonstrated in greek manufacturing firms through a partial observability approach the data set used has resulted from a survey carried out among 161 energy saving technology firm adopters maximum likelihood estimates that arise from an incidental truncation model reveal that the adoption of the energy saving technologies is indeed strongly correlated to the returns of assets that are required in order to undertake the corresponding investments the source of the energy efficiency paradox lies within a wide range of factors policy schemes that aim to increase the adoption rate of energy saving technologies within the field of manufacturing are significantly affected by differences in the size of firms finally mixed policies seem to be more effective than policies that are only capital subsidy or regulation oriented

installed base and compatibility innovation product preannouncements and predation a good is often more valuable to any user the more others use compatible goods the authors show that this effect may inhibit innovation if an installed base exists and transition to a new standard must be gradual early adopters bear a disproportionate share of transient incompatibility costs this can produce excess inertia the installed base however is stranded if the new standard is adopted this may create excess momentum these dynamic effects have strategic implications temporary price cutting can permanently prevent entry and product preannouncements can be critical in innovation these strategic actions have ambiguous welfare effects

technological expectations and adoption of improved technology abstract attention is focused upon the adoption demand rather than the creation supply of new technology which improves from time to time based on the expected flow of technological progress over which the firm demander has no control it must decide either to adopt the current best available technology or to postpone adoption the distinguishing features of the model are that more than one technological innovation is anticipated and expectations about the likelihood of such innovations are revised as time passes since the last innovation our analysis shows that the firm will adopt the current best practice if its technological lag exceeds a certain threshold moreover as time passes without new technological advances it may become profitable to purchase a technology that has been available even though it was not profitable to do so in the past

regulating technological change the strategic reactions of utility companies towards subsidy policies in the german spanish and uk electricity markets abstract this paper focuses on how incumbent electric utilities strategically react to subsidy schemes supporting renewable energy technologies in the uk germany and spain firms coordinate the development of their technological capabilities and their political activities to shape their regulatory environment analysing the diffusion of wind power in these countries we show that the different ways in which firms coordinate their technological and political strategies lead to very different market outcomes both for the firms market share and the size of the overall market although incumbents are usually seen as being resistant to change in energy systems we show that spanish utilities proactively drive the diffusion of wind power we speculate about the relation between the ownership structure of the energy system and its inertia with respect to the integration of new technologies we derive novel policy implications that explicitly take into account the strategic actions of incumbent firms shaping the technological and regulatory system

the relation between marginal product and price in us energy markets implications for climate change policy abstract this paper reports an empirical test of the axioms that describe the relationship between the marginal product and price of factor inputs in us energy markets to do so i estimate a reduced form of a production function that represents the amounts of various energy types that are required to produce a given level of output the partial derivative of this production function is used to calculate the change in output that is generated by a marginal change in the use of coal oil natural gas or electricity a partial adjustment model is used to estimate the relation between the marginal product and price of coal oil natural gas and electricity the results indicate that rational agents manipulate their use of coal oil natural gas and electricity so that the marginal product of these energies adjust to changes in the relative prices of these energies because the marginal products of oil and natural gas are greater than coal less than one heat unit of oil or natural gas is needed to substitute for one unit of coal and this increases the quantity of carbon emissions that can be abated by interfuel substitution the time required to achieve these reductions may be longer than thought previously because of the slow rate at which the relative marginal product adjusts to relative price

eroi and the icelandic society abstract in this paper the societal energy return on investment eroi soc is estimated for iceland between 1960 and the present the results indicate that the overall eroi soc was around 27 1 in the early 1960s and was volatile for a period of time before stabilizing at around 45 1 in 1974 after establishing a strong mix of renewable energy these findings further show that icelanders have generally had access to energy sources with higher eroi than if they had relied on fossil fuels except for the period between 1963 and 1967 if they had relied on fossil fuels alone icelanders would now have access to combined resources with an eroi of around 16 1 likely too low for prosperity and an even lower eroi for long periods of time regarding policies this paper shows that relying on an energy grid mix with an eroi higher than 20 30 1 especially for island nations has the potential to raise the standard of living greatly for policymakers in island nations attention should be given to this relationship between high eroi energy sources with low price volatility and the standard of living

biotechnology boosts to crop productivity in china trade and welfare implications genetically modified gm cotton is widely adopted and the list of gm technologies in trials is impressive in china at the same time there is an active debate on when china should commercialize its gm food crops this paper provides an economy wide assessment of some of the issues surrounding the adoption and commercialization of biotechnology based on unique data from empirical micro level study and field trials in china and a modified gtap model our results indicate that the development of biotechnology has an important impact on china s production trade and welfare welfare gains far outweigh the public biotechnology research expenditures most gains occur inside china and can be achieved independently from biotech unfriendly polices adopted in some industrialized countries

herd behavior the penguin effect and the suppression of informational diffusion an analysis of informational externalities and payoff interdependency this article analyzes a technology adoption process in which the effect of informational spillover interacts with network externalities the interplay of informational externalities and payoff interdependency induces risk averse and clustering behavior in the technology adoption process the analysis differs from the herd behavior literature in focusing on how the herd behavior of subsequent users influences the initial adoption decision moreover herd behavior in this article stems from each agent s desire to inhibit the revelation of new information that can be used in a way detrimental to her rather than from each agent s effort to free ride on information contained in the decisions made by predecessors

innovation diversity and diffusion a self organisation model a number of features of innovation diffusion are identified appropriability diversity expectations selection learning and spillover externalities a dynamic model is formul ated to embed the diffusion question into a more general framework of disequilibrium competition the model incorporates distinct vintage structures reflecting a change in technological trajectory learning by using a nd expectations driven investment rules of thumb simulation studies reveal robust quasi logistic curves but a complicated pattern of net market share gains and losses uncertainty regarding the rationality of early or late adoption it is argued ensures that the requisite behavioral variety is present to generate these diffusion patterns copyright 1988 by royal economic society

technology diffusion and public policy a useful typology of technological change is provided by the schumpeterian trilogy invention the generation of new ideas innovation the development of those ideas through to the first marketing or use of a technology and diffusion the spread of new technology across its potential market until recently policy schemes in most oecd countries have tended to focus predominantly on the invention and innovation or science and r d end of this technology spectrum see e g limpens et al i 992 although it is generally realised that it is the process of diffusion or use of technology that creates productive potential and competitiveness policy initiatives have largely bypassed opportunities to improve the diffusion process if this may seem misplaced emphasis it does in fact reflect the state of the academic literature which is wide ranging and extensive as it relates to policies on r d but small and fragmented as regards policies on diffusion currently a gradual reorientation of policy direction toward diffusion seems to be taking place the us and uk governments for example have recently proposed major technology policy initiatives that despite differences in emphasis both stress the importance of creating an infrastructure conducive to a rapid spread of awareness and knowledge of innovations we argue that although sensible in themselves such policies may be too limited in scope and that a broader policy stance may be needed this paper has two main objectives the first is to provide an overview of why policy intervention in the diffusion process may be desirable and what form it might take this discussion is rather long since to the best of our knowledge there is no published systematic synthesis of the diffusion policy literature though see stoneman i987 for an earlier attempt the second aim is to look at actual diffusion policies and their impacts to make the task manageable we are restricting this paper to a discussion of the diffusion of new process technologies although similar issues apply to new consumer technologies these are not explicitly addressed we also consider diffusion policy only within the context of a given institutional and macroeconomic environment although it may well be that the supply of skilled manpower the nature of the capital market animal spirits and entrepreneurship fiscal and monetary policies will all impact upon the diffusion path improvements in these areas will also impact upon a whole host of other aspects of the economy s performance to use a plea for diffusion policy as a rationale for changes in such areas would be equivalent to the tail wagging the dog and thus they fall outside the remit of this paper

emergent innovation systems and the delivery of clinical services the case of intra ocular lenses abstract this paper is an exploration of the dynamics of technical change in medicine we argue that innovation in medicine is a process that is distributed across time space and epistemic and institutional domains that it entails the entrepreneurial effort of creative individuals as well as the emergence of correlated understanding among heterogeneous agents whose rules of interaction are contingently instituted in socio economic systems along unfolding scientific and technological trajectories we illustrate our arguments through an in depth analysis of a major ophthalmologic innovation the intra ocular lens that has literally transformed the treatment of cataract in the developed world and has the potential to do so in many developing countries we investigate the advancement of clinical knowledge about the disease the development of effective technological capabilities and the co evolution of the supply capacity and demand of a micro innovation system emerged along a specific sequence of interrelated problems and associated solutions which engaged scientists technicians practitioners regulators and patients alike over a period of around three decades

the demand for information and the diffusion of a new product abstract the paper examines the implications of the ability of a consumer to learn about the characteristics of a new product on the diffusion of the product over time the demand for information by the consumer is shown to generate a sigmoid diffusion curve for total sales of the product further it is shown that over time the elasticity of demand along the diffusion curve increases

the determinants of technology adoption the case of the banking firm using data on the adoption of automatic teller machines by firms in the banking industry this study examines the relationship between the decision to adopt new technology and its determinants since banking firms differ considerably in terms of the competitive environments in which they operate focusing on this one innovation in this industry allows a stronger test of the relationship between market structure and the adoption of new technology than has been previously conducted using a failure time estimation procedure we find that larger banks and banks operating in more concentrated local banking markets register a higher conditional probability of adopting this new technology all else equal we also find that other results are consistent with the underlying model and that the bank s regulatory environment shapes its adoption decision in plausible ways

complementarities in organizational design and the diffusion of information technologies an empirical analysis we use a specially designed survey on french firms located in haute savoie to provide empirical evidence suggesting that information and communication technologies adoption is not only influenced by the traditional factors of technology diffusion but also by complementarity effects between strategies organization and information technologies the data collected permitted several advances firstly we could study authentic ict while the recent literature has mainly focused on computer capital stocks or automation tools secondly we constructed measures of the determinants put forward by the models of technology diffusion thirdly we studied three kinds of practices organizational and strategic practices technological choices

bose einstein dynamics and adaptive contracting in the motion picture industry audiences discover what films they like and spread the word information feedback produces bose einstein dynamics in the motion picture box office revenue distribution information cascades generate box office hits and flops the revenue distribution evolves recursively over the run as a mixture of the opening and a stochastic competition among films the motion picture run is decentralized adaptive and self organizing semistationary admission prices local information and contingency rich contracts match the film rental price and the supply of theatrical engagements to demand copyright 1996 by royal economic society

consumption externalities and diffusion in pharmaceutical markets antiulcer drugs we examine the role of consumption externalities in the demand for pharmaceuticals at both the brand level and over a therapeutic class of drugs externalities emerge when use of a drug by others affects its value and or conveys information about efficacy and safety to patients and physicians this can affect the rate of market diffusion for a new entrant and can lead to dominance of one drug despite the availability of close substitutes we use data for h2 antagonist antiulcer drugs to estimate a dynamic demand model and quantify these effects the model has three components an hedonic price equation that measures how the aggregate usage of a drug as well as conventional attributes affect brand valuation equations relating equilibrium market shares to quality adjusted prices and marketing levels and diffusion equations describing the dynamic adjustment process we find that consumption externalities influence both valuations and rates of diffusion and that they operate at the brand and not the therapeutic class level

towards a disequilibrium theory of endogenous economic growth this paper discusses the need for a new approach to economic growth theory the standard theory of growth in equilibrium driven by exogenous uncaused productivity gains has an implication that is both unjustified and perverse from a policy perspective that government intervention of any kind can only introduce constraints and reduce option space thus decreasing potential growth it is argued that growth theory should 1 acknowledge the importance of natural resources especially fossil fuels as a driver of past and present economic growth 2 incorporate an explicit recognition that growth is a consequence of technological innovation especially radical innovation that often responds to natural resource scarcities or other societal needs and 3 explicitly reflect the fact that the important i e scarce factors of production in economics can and do change over time i e from a rural cowboy economy of the past to an urbanized spaceship economy of the future in short it should reflect the fact that necessity is the mother of invention the first and third of these modifications have been proposed before but not in combination the third seems to be new

adoption and diffusion of an innovation of uncertain profitability the argument has frequently been made that the pattern of diffusion associated with most new innovations will typically have certain characteristics a diffusion curve for an innovation is usually defined as the proportion of its potential users who have already adopted as a function of time measured from the first adoption many empirical studies by both economists and other social scientists have shown that diffusion curves nearly always have two distinct characteristics i they are s shaped the proportion adopted is an increasing function of time which is initially convex but eventually becomes concave and ii they tend to be right hand skewed the inflection point occurs at a time corresponding to a proportion adopted which is less than one half so that the function is concave over the greatest amount of time in fact this skewing is occasionally severe enough to make the diffusion curve appear concave everywhere the focus of most empirical studies of innovation diffusion has centered on identification of either the major determinants of the speed of diffusion or the characteristics of firms which determine how long they delay adoption the seminal contributions are griliches 6 study of hybrid corn and mansfield s 121 study of 12 industrial innovations these studies and most of the similar ones following conclude that diffusion is faster for innovations with higher profitability and that large firms tend to be the earliest adopters some studies e g mansfield 121 herregat 71 have attempted to ascertain

the dynamic capabilities of firms an introduction an expanded paradigm is needed to explain how competitive advantage is gained and held firms resorting to resource bas ed strategy attempt to accumulate valuable technology assets and employ an aggressive intellectual property stance however winners in the global marketplace have been firms demonstrating timely responsiveness and rapid and flexible product innovation along with the management capability to effectively coordinate and redeploy internal and external competences this source of competitive advantage dynamic capabilities emphasizes two aspects first it refers to the shifting character of the environment second it emphasizes the key role of strategic management in appropriately adapting integrating and re configuring internal and external organizational skills resources and functional competences toward changing environment 3 only recently have researchers begun to focus on the specifics of developing firm specific capabilities and the manner in which competences are renewed to respond to shifts in the business environment the dynamic capabilities approach provides a coherent framework to integrate existing conceptual and empirical knowledge and facilitate prescription this paper argues that the competitive advanis tage of firms stems from dynamic capabilities rooted in high performance routines z operating inside the firm embedded in the firm s processes and conditioned by its history it offers dynamic capabilities as an emerging paradigm of the modern business j firm that draws on multiple disciplines and advances with the help of industry studies in the usa and elsewhere

network externality perspective of feed in tariffs fit instruments some observations and suggestions abstract existing energy policy frameworks revolving around the acceleration of deployment 1 of renewable energy technology can be broadly classified as the quantity vs price approach with this brief viewpoint this paper suggests another perspective of viewing these instruments in terms of a more fundamental basis whether the deployment in capacity is in terms of a cost minimization approach or a network externality approach we suggest that the generic price or feed in tariff fit approach in subsidizing renewable electricity generation and associated income would create a bandwagon or self propagation effect among users rendering the renewable energy technology spreads like a software or information technology our objective is to raise awareness of this technology dynamics oriented perspective in renewable deployment supplementing the conventional installation subsidies perspective we hope that it would inspire more empirical works and studies relating to the policy implications of this viewpoint

interdependences in the intrafirm diffusion of technological innovations confronting the rational and social accounts of diffusion this article investigates the intrafirm diffusion of technological innovations and the interdependences that exist among rival firms in this process previous research has offered two potential explanations for these interdependences social accounts in which they result from institutional pressures and rational accounts in which firms are interdependent as a result of how adoption by rivals affects expectations about the profitability of the technology the article offers two contributions first we propose a competitive interaction mechanism that is consistent with the fundamentals of rational accounts of diffusion second the empirical analysis shows the dominance of the proposed rational mechanism over social accounts of innovation diffusion in the generation of interdependences in the process of intrafirm diffusion

innovation adoption and diffusion when there are competing innovations abstract firms face a choice between two innovations without knowing which of the two is better each firm has a prior that one of the innovations is better which is updated by bayes rule as trials with the innovations are made a simple decision rule indicating which innovation should be tried given any posterior is derived and used to define an expected diffusion curve for the better innovation this curve has the commonly observed ogive shape even in the absence of any external demonstration effect when the distribution of firm priors belongs to a general class

why ecological economics needs to return to its roots the biophysical foundation of socio economic systems abstract ecological economics was formally established in 1989 with the ambitious vision of developing a new economic paradigm embedding the social and economic systems in the biophysical world ecological economics had its roots in the biophysical understanding of economics that pioneers of the field georgescu roegen 1971 odum 1971 daly 1977 jansson 1984 martinez alier 1987 and others developed while studying the thermodynamic bedrocks shared by natural and social systems subsequently however ecological economics has explicitly but controversially adopted a big umbrella approach to methodological pluralism focusing more on topics such as valuing nature and its functions rather than attempting to understand and quantify the biophysical roots of economic activities biophysical economics was established in response to these concerns focusing more on developing analyses and models of the transformations of nature to generate wealth and approached mostly from an energy and material flows perspective the present paper argues that to achieve its original vision ecological economics must return to its biophysical roots collaboration between the two fields will help the next generation of thinkers to address the socio ecological challenges of the 21st century requiring an energy transformation called for by aspirations such as the green new deal and the un sustainable development goals

competing networks and proprietary standards the case of quadraphonic sound quadraphonic audio systems failed to replace stereo in the 1970s despite backing from all the major manufacturers and recording houses network externalities played a significant role in this episode and the author uses the installed base model of j farrell and g saloner 1986 to explain quad s failure the author finds that the introduction of competing incompatible quadraphonic systems hindered the development of a viable user base and he argues that the systems sponsors introduced their products in a technologically premature state in order to prevent one another from preemptively establishing the quad standard as a result self fulfilling consumer and retailer expectations doomed quadraphonic sound copyright 1990 by blackwell publishing ltd

evolution of erois of electricity until 2050 estimation and implications on prices abstract the eroi for energy returned on invested of an energy technology measures its ability to provide energy efficiently previous studies draw a link between the affluence of a society and the eroi of its energy system and show that erois of renewables are lower than those of fossil fuels logically concerns have been expressed that system wide eroi may decrease during a renewable energy transition first i explain theoretically that the erois of renewables themselves could then decrease as energy efficient fossil fuels would be replaced by less energy efficient renewables in the supply chain then using the multi regional input output model themis i estimate the evolution of erois and prices of electric technologies from 2010 to 2050 for different scenarios global eroi of electricity is predicted to go from 12 in 2010 to 11 in 2050 in a business as usual scenario but down to 6 in a 100 renewable one finally i study the economic implication of a declining eroi an inverse relation between eroi and price is suggested empirically even though theory shows that both quantities may move in the same direction

international diffusion of gains from biotechnology and the european union s common agricultural policy this paper analyses the impact of adopting or rejecting genetically modified gm crops in the european union taking into account the eu common agricultural policy cap in this paper the productivity impact of genetically modified organisms gmos differs across crops taking factor biased technology change into account the transfer of knowledge across countries is modelled as a process of endogenous knowledge spill overs analysis with a multi region applied general equilibrium model shows that the cap protects farm income and production despite non adoption of the more productive gm crops in the eu the eu will forgo substantial benefits in terms of economic welfare if it bans gm imports

rank stock order and epidemic effects in the diffusion of new process technologies an empirical model in this article we construct a general duration model of technology adoption that incorporates the main factors discussed in different theories of diffusion of new process technologies the model is applied to data on diffusion of cnc in the uk engineering industry although we find strong evidence in support of rank and endogenous learning effects there seems to be little evidence in support of the stock and order effects the main factors affecting the diffusion of cnc are found to be endogenous learning firm size industry growth rates the cost of the technology and expected changes in the cost of the technology

human capital information and the early adoption of new technology when producers are uncertain or have imperfect information about the profitability of adopting new technology their adoption behavior depends on the endowment of human capital and the investment in adoption information this study analyzes the role of education experience and information acquisition in the decision to be an early adopter the findings support the hypothesis that adoption decision making is a human capital intensive activity the econometric evidence presented suggests that education and information reduce adoption costs and uncertainty and thereby raise the probability of early adoption adoption behavior is also shown to vary significantly across firm size

greenhouse gas abatement cost curves of the residential heating market a microeconomic approach in this paper we develop a microeconomic approach to deduce greenhouse gas abatement cost curves of the residential heating sector our research is based on a system dynamics microsimulation of private households investment decisions for heating systems to the year 2030 by accounting for household specific characteristics we investigate the welfare costs of different abatement policies in terms of the compensating variation and the excess burden we investigate two policies i a carbon tax and ii subsidies on heating system investments we deduce abatement cost curves for both policies by simulating welfare costs and greenhouse gas emissions to the year 2030 we find that i welfare based abatement costs are generally higher than pure technical equipment costs ii given utility maximizing households a carbon tax is the most welfare efficient policy and iii if households are not utility maximizing a subsidy on investments may have lower marginal greenhouse gas abatement costs than a carbon tax

learning from the behavior of others conformity fads and informational cascades learning by observing the past decisions of others can help explain some otherwise puzzling phenomena about human behavior for example why do people tend to converge on similar behavior why is mass behavior prone to error and fads the authors argue that the theory of observational learning and particularly of informational cascades has much to offer economics business strategy political science and the study of criminal behavior

technological diffusion with social learning this paper attributes the slow diffusion of innovations to an informational externality in the adoption process the profitability of new technologies is uncertain but firing can learn progressively through observing the adoption experience of others given this prospect of social learning every firm would prefer that other firms adopt before it does in the absence of explicit coordination the firms could end up in a sequence of waiting contests this results in staggered adoptions even when all firms are ex ante identical the pace of diffusion is determined endogenously and shown to depend on the characteristics of the innovation copyright 1995 by blackwell publishing ltd

the evolution of markets under entry and standards regulation the case of global mobile telecommunications abstract we analyze the effects of government policies on the evolution of an industry the global mobile telecommunications market i we find a relatively slow diffusion convergence between countries this follows partly from regulatory delay in issuing first licenses yet persisting initial cross country differences also contribute to a lack of convergence ii introducing competition has a strong immediate impact on diffusion but a weak impact afterwards sequential entry is preceded by pre emptive behavior by incumbents this is consistent with the presence of consumer switching costs iii setting a single technological standard accelerates the diffusion of analogue technologies considerably for digital technologies it is too early to draw reliable conclusions yet the available evidence suggests that setting single standards has similar beneficial effects

on the efficient market diffusion of intermittent renewable energies abstract capacity costs of renewable energies have been decreasing dramatically and are expected to fall further making them more competitive with fossils building on an analytically tractable peak load pricing model we analyze how intermittency of renewable energies affects the market diffusion that results from these lower costs in particular once renewables have become competitive by attaining the same levelized cost of electricity lcoe as fossils the marginal increase in efficient capacities due to a further cost reduction varies substantially initially it is small then it rises but it falls again once renewable capacities are large enough to satisfy the whole electricity demand at times of high availability if external costs of fossils are internalized by a pigouvian tax then perfect competition leads to efficient investments in renewable and fossil capacities even though we assume that only a subgroup of consumers can adapt their demand to price fluctuations that are caused by the intermittency of renewables moreover fossils receive a capacity payment through the market for their reliability in serving demand of non reactive consumers maximum electricity prices rise with the share of renewables if regulators impose a price cap this initially raises investments in renewables but the effect may reverse if the share of renewables is large

analysis of resource potential for china s unconventional gas and forecast for its long term production growth abstract china is vigorously promoting the development of its unconventional gas resources because natural gas is viewed as a lower carbon energy source and because china has relatively little conventional natural gas supply in this paper we first evaluate how much unconventional gas might be available based on an analysis of technically recoverable resources for three types of unconventional gas resources shale gas coalbed methane and tight gas we then develop three alternative scenarios of how this extraction might proceed using the geologic resources supply demand model based on our analysis the medium scenario which we would consider to be our best estimate shows a resource peak of 176 1 billion cubic meters bcm in 2068 depending on economic conditions and advance in extraction techniques production could vary greatly from this if economic conditions are adverse unconventional natural gas production could perhaps be as low as 70 1 bcm peaking in 2021 under the extremely optimistic assumption that all of the resources that appear to be technologically available can actually be recovered unconventional production could amount to as much as 469 7 bcm with peak production in 2069 even if this high scenario is achieved china s total gas production will only be sufficient to meet china s lowest demand forecast if production instead matches our best estimate significant amounts of natural gas imports are likely to be needed

a dynamic analysis of the adoption of a new technology the case of optical scanners two p roportional hazard models are used to investigate the differingeffects of marke t structure variables on the conditional probabilityof a firm initially adoptin g the new technology of optical scanners as the innovation spreads through the f ood store industry during the early stage leading firms with large average sto re size which are not members of chains and which operate in less concentrated m arkets with higher incomes and wage rates tend to adopt scanners sooner later on differences in seller concentration market share and size become less impo rtant as other firms follow prior adoptions copyright 1987 by mit press

the effect of network structure in industrial diffusion processes abstract the development and diffusion of innovations involves groups of organizations with many different roles who interact with each other suppliers adopters third parties etc this paper examines the nature of the communication networks that exist between adopting organizations and from third parties and suppliers to adopters quantitative models of diffusion often assume that information about innovations flows along pre existing links that this information flows from adopters to non adopters directly and that there is perfect mixing in the population i e every actor has an equal chance of communicating with every other actor these are strong assumptions which should be subject to testing we investigate the impact of differing network topologies of communications and alternative models of social contagion on observed adoption patterns network topologies are also extended beyond the focal industry to include suppliers consultants and other customers we use a simulation model to test the effect of departures from traditional assumptions on the diffusion pattern and undertake an empirical field study to examine the prevalence of those departures in one specific industry our simulation findings suggest that network structure can have a substantial effect on the manner in which innovations diffuse while innovation specific communication links and communication through third parties does not change the shape of the penetration trajectory as much as it alters the places in the process where salesforce effort can offer the most leverage the empirical study shows strong evidence of imperfect mixing that both pre existing and innovation specific communication links are used and that communication through third parties may be as important to the diffusion process as direct links from adopters to potential adopters

is energy intensity important for the productivity growth of eet adopters abstract energy efficient technologies eet have attracted strong interest because of their role in reducing environmental damage their adoption however remains rather low while their impact on productivity is substantial and differentiating with respect to technological characteristics energy intensity being such an obvious characteristic could be employed to classify eet adopters thus giving rise to two heterogeneous technologies i e those corresponding to firms of low and high energy consumption hence this paper examines the impact of energy intensity on the productivity growth of firms adopting eet in varying time intervals through a metafrontier based framework while also decomposing that impact in terms of technical efficiency and scale efficiency changes the analysis is complemented by examining the role of firm specific characteristics on the productivity growth through linear regression

the ambiguity of innovation drivers the adoption of information and communication technologies by public water utilities abstract information and communication technologies have the potential to increase productivity improving efficiency and eventually raising the quality of water services although this potential is recognized great variation exists in the way water utilities adopt information and communication technologies based on literature review and empirical data drawn from the three case studies a municipality in greece an airport in italy and a water utility in the netherlands developed under the eu funded waternomics project the paper highlights how environmental organizational and individual factors explain technology adoption the paper pays particular attention to the idiosyncrasies of the water services sector which influence this process these include include the social and conomic importance of water supply the monopolistic nature of the sector and increased commercialization of public water utilities our cases suggest that drivers of technology adoption appear to be somewhat ambiguous in the water services sector in that they impact adoption in diverse locations differently our cases also suggest is that the prioritization of the factors that determine adoption are dynamic and change over time

the diffusion of clean technologies a review with suggestions for future diffusion analysis abstract this article gives an overview of the literature on clean technology diffusion followed by suggestions for future analysis findings from diffusion analysis are presented in the form of 10 stylised facts helping the reader to see the forest for the trees the overall conclusion is that the diffusion of clean technology same as the diffusion of normal innovations is governed by endogenous mechanism epidemic learning and learning economies and by exogenous mechanisms policy is important for clean technology diffusion but other factors are important too the characteristics of the clean technology absorptive capacities of potential adopters and the age structure of capital it is often overlooked that companies have a choice they can choose between an end of pipe solution a process change adaptation and a change of process substitution this means that the diffusion and evolution of one clean technology will be at the expense of the diffusion of another clean technology something overlooked in studies on clean technology diffusion further research is needed on the influence of public policy on clean technology choice expectations about learning economies and prices adjustment costs network externalities and complementary innovations on clean technology adoption choices

the cleansing effect of recessions the authors investigate industry response to cyclical variations in demand production units that embody the newest process and product innovations are continuously being created and outdated units are being destroyed although outdated units are the most likely to turn unprofitable and be scrapped in a recession they can be insulated from the fall in demand by a reduction in creation the structure of adjustment costs plays a determinant role in the responsiveness of those two margins the calibrated model matches the relative volatilities of the observed manufacturing job creation and destruction series and their asymmetries over the cycle copyright 1994 by american economic association

international diffusion and intellectual property rights an empirical analysis abstract does a stronger intellectual property rights regime lead to the faster diffusion of new products and technology while there is a presumption that this is the case our analysis of data on the international release patterns of hollywood movies suggests a more complex story although moderate standards of ipr encourage the spread of movies either very weak or very strong property rights tend to slow the speed with which american movies are released abroad this empirical finding is robust to a wide variety of specifications overall it appears that while some recognition of ipr may encourage diffusion very strong ipr may actually retard the speed of diffusion

market segmentation and the diffusion of quality enhancing innovations the case of downhill skiing we report econometric results concerning the diffusion of detachable chairlifts in the united states that provide the first empirical evidence that the adoption of a technological innovation by a firm decreases the likelihood that a local competitor will also adopt it we model the effect that an innovation in service speed has on a f s incentive to differentiate the quality of its service from that of its competitors in our model the incentive to adopt is negatively related to the number of competitors who have already adopted our empirical results support this hypothesis

technology adoption learning spillovers and the optimal duration of patent based monopolies abstract the paper analyses an often overlooked aspect of the patent system namely that a monopoly franchise for production of a new good could lead to a second best welfare optimum event when there was no future prospect of inventions being induced by the patent it is shown that a paten may improve economic welfare relative to a regime of competitive supply when there are learning externalities or spillovers from experience in the process of production comparative statics show that stronger learning effects at low levels of experience tend to strengthen the case for ex post grant of a monopoly franchise

political economy based institutional industry complex and sustainable development the case of the salt chemical industry in huai an china abstract this article explains how the salt chemical industry may evolve over time from a high energy consumption based industry complex in the local community to a consolidated pro growth pluralist regime at the urban scale the salt chemical industry is resisting to restructure to a sustainable environmental friendly economic system by spilling over in the form of pro growth political economic coalition in local society theories of the logan and molotch s growth machine stone s urban regime together with the extension of unruh s thesis concerning the characteristics of lock in in the technological or institutional economics approach were used to propose an enlarged lock in political economic framework and pro growth institutional industry complex iic it is further used to explain the consensus building of the pro growth governance a study of the salt chemical and new material industry park in the huai an metropolitan area china serves as an illustrative case the article also suggests that the path dependence followed in constructing a pro growth coalition could serve as a program to unlock the pro growth institutional industry complex of salt chemical industry and foster the anti coalition needed

efficient feed in tariff policies for renewable energy technologies feed in tariff fit policies aim at driving down the cost of renewable energy by fostering learning and accelerating the diffusion of green technologies under fit mechanisms governments purchase green energy at tariffs that are set above market price the success or failure of fit policies in turn critically depend on how these tariffs are determined and adjusted over time this paper provides insights into designing cost efficient and socially optimal fit programs our modeling framework captures key market dynamics as well as investors strategic behavior in this framework we establish that the current practice of maintaining constant profitability is theoretically rarely optimal by contrast we characterize a no delay region in the problem s parameters such that profitability should strictly decrease over time if the diffusion and learning rates belong to this region in this case investors never strategically postpone their investment to a later period when the diffusion and learning rates

the energy emissions trap abstract the requirement to reduce emissions to avoid potentially dangerous climate change implies a dilemma for societies heavily dependent on fossil fuels reducing emissions will necessitate the transition from relatively high eroi dispatchable fossil fuels to a combination of relatively low eroi intermittent renewables and geographically limited non intermittent renewables as renewable capacity requires energy to construct there is an initial fossil fuel cost to creating new renewable capacity an insufficiently rapid transition to renewables will imply a scenario in which it is impossible to avoid either transgressing emissions ceilings or facing energy shortages we term this the energy emissions trap in this paper we construct a mathematical model termed eetrap that builds the eroi metric and the energy characteristics of renewable generation into a macroeconomic framework eetrap is used for simulation analysis to test how differing assumptions about the eroi of intermittent renewables will affect the time path of renewable investment necessary to escape the energy emissions trap for all runs of the model the renewable investment rate by 2050 is significantly larger than the current energy investment rate for declining intermittent renewable eroi the renewable investment rate crowds out other forms of investment leading to a declining economic growth rate

economics for the future beyond the superorganism abstract our environment and economy are at a crossroads this paper attempts a cohesive narrative on how human evolved behavior money energy economy and the environment fit together humans strive for the same emotional state of our successful ancestors in a resource rich environment we coordinate in groups corporations and nations to maximize financial surplus tethered to energy tethered to carbon at global scales the emergent result of this combination is a mindless energy hungry co2 emitting superorganism under this dynamic we are now behaviorally growth constrained and will use any means possible to avoid facing this reality the farther we kick the can the larger the disconnect between our financial and physical reality becomes the moment of this recalibration will be a watershed time for our culture but could also be the birth of a new systems economics and resultant different ways of living the next 30 years are the time to apply all we ve learned during the past 30 years we ve arrived at a species level conversation

emerging value chains within the bio economy structural changes in the case of phosphate recovery abstract the needed transition from a fossil to a bio based economy fosters the utilization of biological resources derived from recycled low value by products and waste streams chain actors face multiple challenges associated with the adoption of novel processing technologies bio based technologies might be related to high switching costs missing downstream processing technologies lack of quality standards missing industry standards emerging regulatory frameworks moreover as previously unrelated actors form new relationships value chains are moving towards new structural changes this paper thus seeks to explore the challenges associated with the emergence of novel value chains with an exploratory case study approach that reviews a new process of recovering phosphate a typical scarce and fundamental resource from rapeseed oil press cakes the contribution of our paper is thus not only to provide conclusions for this specific case but also and more importantly to present a blueprint for other cases of scarce resources that require the establishment of novel supply chains to foster cascading usage of by products expert interviews with different value chain actors have been conducted to investigate arising challenges and derive implications and a further research agenda despite the advantages of the bio based process interviews revealed several challenges associated with the emergence of novel value chains hesitation of respondents in making new investments in terms of equipment and know how missing complementary competencies and difficulties in integrating different industrial sectors to engage in cross industry innovation such as food processing rapeseed oil cakes and specialty chemicals mineral phosphate and its derivatives these exploratory results open the way for some useful recommendations enabling us to propose an agenda for further research and policy development in areas such as development of synergies between academia and industry formulation of management strategies to support the flexibility of firms to capture opportunities associated with by product valorization building a systemic approach at a local level to implement bio based technology clusters

energy expenditure economic growth and the minimum eroi of society we estimate energy expenditure for the us and world economies from 1850 to 2012 periods of high energy expenditure relative to gdp from 1850 to 1945 or spikes 1973 74 and 1978 79 are associated with low economic growth rates and periods of low or falling energy expenditure are associated with high and rising economic growth rates e g 1945 1973 over the period 1960 2010 for which we have continuous year to year data for control variables capital formation population and unemployment rate we estimate that statistically in order to enjoy positive growth the us economy cannot afford to spend more than 11 of its gdp on energy given the current energy intensity of the us economy this translates in a minimum societal eroi of approximately 11 1 or a maximum tolerable average price of energy of twice the current level granger tests consistently reveal a one way causality running from the level of energy expenditure as a fraction of gdp to economic growth in the us between 1960 and 2010 a coherent economic policy should be founded on improving net energy efficiency this would yield a double dividend increased societal eroi through decreased energy intensity of capital investment and decreased sensitivity to energy price volatility

energy eroi and quality of life abstract the near and long term societal effects of declining eroi are uncertain but probably adverse a major obstacle to examining social implications of declining eroi is that we do not have adequate empirical understanding of how eroi is linked directly or indirectly to an average citizen s ability to achieve well being to evaluate the possible linkages between societal well being and net energy availability we compare these preliminary estimates of energy availability 1 eroi at a societal level 2 energy use per capita 3 multiple regression analyses and 4 a new composite energy index lambert energy index to select indicators of quality of life hdi percent children under weight health expenditures gender inequality index literacy rate and access to improved water our results suggest that energy indices are highly correlated with a higher standard of living we also find a saturation point at which increases in per capita energy availability greater than 150 gj or eroi above 20 1 are not associated with further improvement to society

flying more efficiently joint impacts of fuel prices capital costs and fleet size on airline fleet fuel economy abstract we investigate the factors that affect airlines choice of fleet fuel economy using aircraft level data for 1267 airlines in 174 countries larger and newer aircraft are usually more fuel efficient controlling for the effect of aircraft size and age we find that the technically achievable fleet fuel economy improves with the size of airlines and the price of fuel and worsens with higher capital costs the elasticity of fuel economy with respect to the price of fuel is between 0 07 and 0 13 we find evidence for regional differences in fleet fuel economy that are attributable to the adoption of distinct groups of technologies

the potential for improvements in energy efficiency and co2 emissions in the eu27 cement industry and the relationship with the capital budgeting decision criteria this paper performs a cost effectiveness analysis of some of the best available technologies bat that can contribute to decreasing the energy consumption and co2 emissions in the european union s eu27 cement industry several capital budgeting decision criteria have been used the payback period the net present value and the internal rate of return to study whether or not an investment should be considered worthwhile the results show that independent of the capital budgeting decision criteria used the number of cost effective retrofitting possibilities available is large compared to the rate of improvements that the industry undertakes annually this shows the insensitivity of the industry to financial criteria when it comes to making their investment decisions the possible thermal energy improvement in the clinker production if all these bats were implemented has been quantified to be around 10 this achievement would place the cement industry in the upper bound of the benchmark range for clinker manufacture however considering the delays observed nowadays in terms of diffusion of bats in the cement industry it requires a conducive policy environment that combines support for both technology development and to their deployment

limits to growth redux a system dynamics model for assessing energy and climate change constraints to global growth abstract this study investigates the notion of limits to socioeconomic growth with a specific focus on the role of climate change and the declining quality of fossil fuel reserves a new system dynamics model has been created the world energy model wem is based on the world3 model the limits to growth meadows et al 2004 with climate change and energy production replacing generic pollution and resources factors wem also tracks global population food production and industrial output out to the year 2100 this paper presents a series of wem s projections each of which represent broad sweeps of what the future may bring all scenarios project that global industrial output will continue growing until 2100 scenarios based on current energy trends lead to a 50 increase in the average cost of energy production and 2 4 2 7 c of global warming by 2100 wem projects that limiting global warming to 2 c will reduce the industrial output growth rate by 0 1 0 2 however wem also plots industrial decline by 2150 for cases of uncontrolled climate change or increased population growth the general behaviour of wem is far more stable than world3 but its results still support the call for a managed decline in society s ecological footprint

eroi of different fuels and the implications for society abstract all forms of economic production and exchange involve the use of energy directly and in the transformation of materials until recently cheap and seemingly limitless fossil energy has allowed most of society to ignore the importance of contributions to the economic process from the biophysical world as well as the potential limits to growth this paper centers on assessing the energy costs of modern day society and its relation to gdp our most important focus is the characteristics of our major energy sources including each fuel s energy return on investment eroi the eroi of our most important fuels is declining and most renewable and non conventional energy alternatives have substantially lower eroi values than traditional conventional fossil fuels at the societal level declining eroi means that an increasing proportion of energy output and economic activity must be diverted to attaining the energy needed to run an economy leaving less discretionary funds available for non essential purchases which often drive growth the declining eroi of traditional fossil fuel energy sources and the effect of that on the world economy are likely to result in a myriad of consequences most of which will not be perceived as good

entry exit and diffusion with learning by doing early entry has the advantage of higher revenues per unit of output early on late entry has the benefit of learning from the experience of earlier entrants and hence lower production costs the advantages are balanced off in a continuous time perfect foresight equilibrium competition generates s shaped diffusion and staggered entry and exit a monopolist will innovate less than a competitive industry but the innovation that he does do he will do sooner copyright 1989 by american economic association

the diffusion of new technology and the market for an innovation this article shows that the diffusion of a capital embodied process innovation results from a pattern of decreasing incremental benefits and adoption costs for later adoptions strategic behavior is inessential to this finding we develop a method for comparing diffusion rates for different market structures in the capital equipment market we consider cases with market power on the seller s side of the market and on the buyers side of the market a case with no market power and the welfare optimal case we find that a joint venture adopts an innovation more slowly than other market regimes to protect existing capital investments and that the adoption rate is slower than is socially optimal a monopoly supplier on the other hand adopts at a rate faster than is socially optimal this result is usually also the case when there is no market power finally we show that the monopoly supplier accelerates adoptions faster than in the case where there is no market power but retards later adoptions market power thus makes a difference in diffusion rates and on which side of the market that power lies makes a considerable difference

models of technology diffusion abstract the literature on new technology diffusion is vast and it spills over many conventional disciplinary boundaries this paper surveys the literature by focusing on alternative explanations of the dominant stylized fact that the usage of new technologies over time typically follows an s curve the most commonly found model which is used to account for this model is the so called epidemic model which builds on the premise that what limits the speed of usage is the lack of information available about the new technology how to use it and what it does the leading alternate model is often called the probit model which follows from the premise that different firms with different goals and abilities are likely to want to adopt the new technology at different times in this model diffusion occurs as firms of different types gradually adopt it there are actually many ways to generate an s curve and the third class of models which we examine are models of density dependence popularized by population ecologists in these models the twin forces of legitimation and competition help to establish new technologies and then ultimately limit their take up finally we look at models in which the initial choice between different variants of the new technology affect the subsequent diffusion speed of the chosen technology such models often rely on information cascades which drive herd like adoption behaviour when a particular variant is finally selected

consumer learning and hybrid vehicle adoption we study the effect of differences in product quality on new technology diffusion we propose a model in which heterogeneity in perceived product quality affects consumer adoption if consumers experientially infer the quality of a technology an increase in initial exposure to a low quality product may inhibit subsequent diffusion incentives intended to speed up adoption may in fact have the opposite effect if they propagate low quality signals we examine the predictions of the model using sales data for 11 hybrid vehicle models between 2000 and 2006 consistent with press reports that the first generation insight was perceived to be of lower quality than the first generation prius we find that conditional on overall hybrid vehicle adoption in the first 2 years locations with a relatively high prius market share experienced faster subsequent adoption than states with a relatively high insight market share we estimate the elasticity of new hybrid sales with respect to the prius penetration rate is 0 30 0 58 while the elasticity with respect to the insight penetration rate is 0 14 to 0 44

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

technology adoption with limited foresight and uncertain technological learning most previous optimization models on technology adoption assume perfect foresight over the long term in reality decision makers do not have perfect foresight and the endogenous driving force of technology adoption is uncertain with a stylized optimization model this paper explores the adoption of a new technology its associated cost dynamics and technological bifurcations with limited foresight and uncertain technological learning the study shows that when modeling with limited foresight and technological learning 1 the longer the length of the decision period the earlier the adoption of a new technology and the value of a foresight can be amplified with a high learning rate however when the decision period is beyond a certain length further extending its length has little influence on adopting the new technology 2 with limited foresight decisions aiming at minimizing the total cost of each decision period will commonly result in a non optimal solution from the perspective of the entire decision horizon and 3 the range of technological bifurcation is much larger than that with perfect foresight but uncertainty in technological learning tends to reduce the range by removing the early adoption paths of a new technology

the diffusion of computers and the distribution of wages abstract when the costs are decreasing workers adopt technology at the point where the costs equal the increased productivity output per worker increases immediately while productivity benefits increase only gradually if costs continue to fall as a result workers in computer adopting labor market groups experience an immediate fall in wages due to increased supply on the other hand adopting workers experience wage increases with some delay this model explains why increased computer use does not immediately lead to higher wage inequality more specifically the results of the model are shown to be consistent with the question why within group wage inequality among skilled workers as a result of computer technology adoption in the united states increased in the 1970s while between group wage inequality and within group wage inequality among the unskilled did not start to increase until the 1980s the model also predicts that the more compressed german wage structure leads to a lagged diffusion of computer technology along with smaller changes in wage inequality our empirical analysis suggests that this is consistent with the actual developments in germany since the 1980s finally the theoretical predictions seem to be of the right magnitude to explain the empirical quantities observed in the data

the rapid adoption of data driven decision making abstract we provide a systematic empirical study of the diffusion and adoption patterns of data driven decision making ddd in the u s using data collected by the census bureau for a large representative sample of manufacturing plants we find that ddd rates nearly tripled 11 30 between 2005 and 2010 this rapid diffusion along with results from a companion paper are consistent with case based evidence that ddd tends to be productivity enhancing yet certain plants are significantly more likely to adopt than others key correlates of adoption are size presence of potential complements such as information technology and educated workers and firm learning

striving for a large market evidence from a general purpose technology in action several scholars have tried to focus on growth accounting of specific examples of general purpose technologies gpts but what are the factors that might make a general purpose technology succeed or fail once the invention has been triggered this paper is a preliminary answer to this question and attempts to study gpts from an ex ante perspective trying to understand what is the behaviour and performance of the producer firms and what the factors are that can favour or hamper their diffusion in the application sectors the paper follows a historical perspective on a control technology introduced in the last few decades by a silicon valley start up company

demand and supply in new markets diffusion with bilateral learning i explore the endogenous joint evolution of demand and supply in new markets firms and consumers learn in a bayesian fashion by observing the behavior of other firms and consumers respectively as a result endogenous information diffusion takes place on both sides of the market in equilibrium entry occurs in waves and its level depends on two distinct informational effects the model identifies an externality that provides a natural explanation for s shaped diffusion paths entry reveals information to the consumers about the value of the new product and thus early waves of entry affect the expected profitability of subsequent entry

connecting net energy with the price of energy and other goods and services net energy is intuitively compelling and useful in calculating total impacts e g primary energy greenhouse gases land use and water requirements of delivering useful energy to the larger economy however it has little policy impact unless connected quantitatively to the price of energy and other goods and services i present an input output io based method to do this the method is illustrated by a two sector model fitted to u s io economic data in an io characterized system the energy returned on energy invested eroi and the energy intensity of energy are directly related however eroi and prices are not uniquely related because they depend differently on four independent io coefficients representing internal structure of and the relationship between the energy sector and the rest of the economy if only one of these coefficients varies then eroi does uniquely determine prices uncertainties in the io coefficients as well as persistent issues of choosing system boundary and aggregating diverse energy types further complicate the eroi price connection in this context i review two recent empirical comparisons of u s oil and gas prices and eroi for 1954 2007