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

adaptive learning and equilibrium selection in experimental coordination games an arch 1 approach abstract we analyze and estimate an adaptive learning model which explicitly considers strategic uncertainty in order to provide a unified explanation of the patterns of equilibrium selection in j van huyck r battalio and r beil s 1990 amer econ rev 80 234 248 1991 quart j econ 106 885 910 experimental coordination games the leaning dynamics follow an autoregressive conditional heteroskedasticity process of order 1 arch 1 we find that arch captures the persistence in players assessments of uncertainty as they update their beliefs provides a reduced form for differences of unknown form in players beliefs without relying on any assumptions on their probabilistic structure and yields a parsimonious parametric description of the learning dynamics journal of economic literature classification numbers c92 c73 c51 c25

smallholder market participation concepts and evidence from eastern and southern africa abstract this paper reviews the evidence on smallholder market participation with a focus on staple foodgrains i e cereals in eastern and southern africa in an effort to help better identify what interventions are most likely to break smallholders out of the semi subsistence poverty trap that appears to ensnare much of rural africa the conceptual and empirical evidence suggests that interventions aimed at facilitating smallholder organization at reducing the costs of intermarket commerce and perhaps especially at improving poorer households access to improved technologies and productive assets are central to stimulating smallholder market participation and escape from semi subsistence poverty traps macroeconomic and trade policy tools appear less useful in inducing market participation by poor smallholders in the region

ecosystem services from eye opening metaphor to complexity blinder abstract what started as a humble metaphor to help us think about our relation to nature has become integral to how we are addressing the future of humanity and the course of biological evolution the metaphor of nature as a stock that provides a flow of services is insufficient for the difficulties we are in or the task ahead indeed combined with the mistaken presumption that we can analyze a global problem within a partial equilibrium economic framework and reach a new economy project by project without major institutional change the simplicity of the stock flow framework blinds us to the complexity of the human predicament the ecosystem services approach can be a part of a larger solution but its dominance in our characterization of our situation and the solution is blinding us to the ecological economic and political complexities of the challenges we actually face

piketty and the growth dilemma revisited in the context of ecological economics 2017 elsevier b v piketty s capital has provoked considerable debate regarding inequality the existence of increasing inequality creates a challenge for ecological economics in this paper we set out some of the problems inherent in piketty s approach and how they are addressed from the point of view of ecological economics we use jackson and victor s response as a point of departure to make several points piketty s work involves an unreconciled inconsistency between his laws and the institutional context which becomes problematic when one starts to think about inevitability he simply assumes away ecological problems to make future forecasts for inequality as such his forecasts are undermined since ecological issues are fundamental to any viable future economy furthermore piketty effectively reproduces rather than contests the mainstream practice of delegating ecological issues to a sub discipline jackson and victor meanwhile focus on the mainstream economic aspect of piketty s work and construct a model to contest a model in so doing they provide an ideational response to what is also a problem of ideological frameworks though it can be important to contest an idea they inadvertently through family resemblance contribute to the reproduction of the problematic position of ecological concerns within dominant ways of conceiving economics

technology adoption impact and extension in developing countries agriculture a review of the recent literature given the stagnant agricultural productivity and persistent food insecurity in low income countries notably in sub saharan africa ssa there has been continued interest in the adoption of new technology and its impact on productivity in these regions interestingly there are signs of green revolution in maize and rice in ssa reflected in sharply increasing yield trends in advanced regions to increase crop yields and sustain yield gains recent case studies of technology adoption unanimously recommend the adoption of integrated farm management systems particularly in ssa on the other hand since the 2010s there have been increasing numbers of studies on social network or farmer to farmer technology extension these studies explore more efficient extension systems than traditional public sector extension approaches this article reviews both recent case studies of technology adoption and its productivity impacts as well as studies on agricultural extension to identify common findings shortcomings and major remaining issues

strong sustainability critical natural capital and the capability approach this article is an attempt to conceptually improve the notion of strong sustainability by creating a rapprochement between its core concept critical natural capital and the capability approach we first demonstrate that the capability approach constitutes a relevant framework for analysing the multiple links between human well being and critical natural capital second we demonstrate that the rapprochement between critical natural capital and the capability approach can form both the normative basis and the informational basis for a deliberative approach to human development which embraces a strong sustainability perspective this conceptual rapprochement as illustrated in our case study opens up avenues of research towards the practical implementation of human development projects from a strong sustainability perspective

the place of the capability approach within sustainability economics the connections between the capability approach and sustainability economics have been explored recently i argue here that for engaging in a more substantive study of those connections we must first understand the place of the capability approach within the history of economic thought as a second stage of the revival of classical surplus theory once this is clear we can then use the capability approach in order to specify concepts such as well being surplus scarcity and sustainable reproduction which are essential for the development of sustainability economics

input subsidy programs in sub saharan africa a synthesis of recent evidence input subsidy programs have once again become a major plank of agricultural development strategies in africa ten african governments spend roughly us 1 billion annually on input subsidy programs isps amounting to 28 6 of their public expenditures on agriculture this article reviews the microlevel evidence on isps undertaken since the mid 2000s we examine the characteristics of subsidy beneficiaries crop response rates to fertilizer application and their influence on the performance of subsidy programs the impacts of subsidy programs on national fertilizer use and the development of commercial input distribution systems and finally the impact of isps on food price levels and poverty rates the weight of the evidence indicates that the costs of the programs generally outweigh their benefits findings from other developing areas with a higher proportion of crop area under irrigation and with lower fertilizer prices factors that should provide higher returns to fertilizer subsidies than in africa indicate that at least a partial reallocation of expenditures from fertilizer subsidies to r d and infrastructure would provide higher returns to agricultural growth and poverty reduction however because isps enable governments to demonstrate tangible support to constituents they are likely to remain on the african landscape for the foreseeable future hence the study identifies ways in which benefits can be enhanced through changes in implementation modalities and complementary investments within a holistic agricultural intensification strategy among the most important of these are efforts to reduce the crowding out of commercial fertilizer distribution systems and programs to improve soil fertility to enable farmers to use fertilizer more efficiently the challenges associated with achieving these gains are likely to be formidable

the relevance of epistemic analysis to sustainability economics and the capability approach abstract this paper considers how epistemic analyses birkin and polesie 2011 foucault 1970 foucault 1990a foucault 1990b may assist with the development of sustainability economics bartelmus 2010 baumgartner and quaas 2010a baumgartner and quaas 2010b and soderbaum 2011 and the capability approach ballet et al 2011 martins 2011 rauschmayer and lesmann 2011 scerri 2012 it was the french social theorist michel foucault 1926 1984 who coined the term episteme to refer to the possibility of knowledge that determines the development of thought and knowledge in a given period for foucault epistemes were the buried foundations of knowledge that his epistemic archaeology could unearth in 2007 foucault was identified as the most cited author of books in the humanities by thomson reuters isi web of science this paper begins with a brief definition and description of epistemic analyses a summary analysis of the modern episteme and neoclassical economics is then provided and this is followed by outline evidence for the emerging episteme finally the opportunity is considered for the emerging episteme to reinforce and enhance sustainability economics and the capability approach

state conditional fertilizer yield response on western kenyan farms 15 16 17 we acknowledge with gratitude support from the rockefeller foundation the united states agency for 18 international development usaid leadership enhancement in agriculture program leap and the 19 coupled natural and human systems program of the biocomplexity initiative of the national science 20 foundation through grant bcs 0215890 the world agroforestry center icraf graciously hosted 21 the lead author for part of the research and provided soil test results we are also grateful to james

ecosystems strong sustainability and the classical circular economy abstract in this article i argue that notions such as ecosystem services and strong sustainability can be best understood and developed within the theoretical framework advanced by the classical political economists in which a circular conception of the economy is provided i also argue that the development of notions such as ecosystem services and strong sustainability has been constrained by the dominance of neoclassical economics which provides a linear conception of the economy and leads to an emphasis on weak sustainability which in turn springs from an emphasis on substitutability and aggregate capital when assessing the relevance of classical political economy for studying ecosystem services and strong sustainability i consider not only the contributions of the classical political economists but also more recent contributions which draw upon the classical perspective such as piero sraffa s and amartya sen s

soil quality and fertilizer use rates among smallholder farmers in western kenya studies of fertilizer use in sub saharan africa have been dominated by analyses of economic and market factors having to do with infrastructure institutions and incentives that prevent or foster increased fertilizer demand largely ignoring how soil fertility status conditions farmer demand for fertilizer we apply a switching regression model to data from 260 farm households in western kenya in order to allow for the possibility of discontinuities in fertilizer demand based on a soil carbon content scc threshold we find that the usual factors reflecting liquidity and quasi fixed inputs are important on high scc plots but not on those with poorer soils external inputs become less effective on soils with low scc hence the discernible shift in behaviors across soil quality regimes for many farmers improved fertilizer market conditions alone may be insufficient to stimulate increased fertilizer use without complementary improvements in the biophysical conditions that affect conditional factor demand

green circular bio economy a comparative analysis of sustainability avenues despite their evidently different assumptions and operationalization strategies the concepts of circular economy green economy and bioeconomy are joined by the common ideal to reconcile economic environmental and social goals the three concepts are currently mainstreamed in academia and policy making as key sustainability avenues but a comparative analysis of such concepts is missing the aim of this article is thus to comprehensively analyse the diversity within and between such concepts the results are drawn from a bibliometric review of almost two thousand scientific articles published within the last three decades coupled with a conceptual analysis we find that for what concerns environmental sustainability green economy acts as an umbrella concept including elements from circular economy and bioeconomy concepts e g eco efficiency renewables as well as additional ideas e g nature based solutions in particular circular economy and bioeconomy are resource focused whereas in principle green economy acknowledges the underpinning role of all ecological processes regarding the social dimension green economy is more inclusive of some aspects at local level e g eco tourism education while there is an emerging discussion in bioeconomy literature around local processes in terms of biosecurity and rural policies when considering weak strong sustainability visions all concepts remain limited in questioning economic growth by comparing the different sustainability strategies promoted by these concepts we do not advocate for their substitutability but for their clarification and reciprocal integration the findings are discussed in light of the concepts synergies and limits with the purpose to inform research and policy implementation

understanding fertilizer adoption and effectiveness on maize in zambia abstract increased fertilizer use will likely be crucial for raising and sustaining farm productivity in africa but adoption may be limited by ineffectiveness under certain conditions this article quantifies the impacts of soil characteristics on maize response to fertilizer in zambia using a nationally representative sample of 1453 fields combining economic farm management and soil analysis data depending on soil regimes average maize yield response estimates range from insignificant 0 to 7 maize kg per fertilizer kg for the majority of farmers the estimated average value cost ratio is between 1 and 2 meaning fertilizer use would be fiscally rational barring uncertainty and transfer costs since transfer costs exist and outcomes are uncertain however many farmers may sensibly pause before deciding whether to adopt fertilizer this suggests shifting the emphasis of chronically low fertilizer use in africa away from explanations of market failure toward greater emphasis on improving fertilizer efficacy

the history of ecosystem services in economic theory and practice from early notions to markets and payment schemes article i nfo this paper reviews the historic development of the conceptualization of ecosystem services and examines critical landmarks in economic theory and practice with regard to the incorporation of ecosystem services into markets and payment schemes the review presented here suggests that the trend towards monetization and commodification of ecosystem services is partly the result of a slow move from the original economic conception of nature s benefits as use values in classical economics to their conceptualization in terms of exchange values in neoclassical economics the theory and practice of current ecosystem services science are examined inthelight ofthis historicaldevelopment from thisreview we conclude thatthefocus onmonetary valuation and payment schemes has contributed to attract political support for conservation but also to commodify a growing number of ecosystem services and to reproduce the neoclassical economics paradigm and the market logic to tackle environmental problems

a note on sustainability economics and the capability approach sustainability economics attempts to reconcile efficiency criteria with those of social justice in a context of environmental concern this article aims at highlighting the fact that the capability approach offers an interesting perspective for the foundation of sustainability in economics it primarily focuses on the major role that freedom brings as a normative basis for well being and adds new insights for our understanding of human and environment relationship through the study of the constraints and opportunities that affect the individual the final section of this article asks us to reconsider our nature conservation choices by acknowledging the restrictive impact that they have on individual freedoms

environment justice and the capability approach in recent years several studies have attempted to combine the capabilities approach with sustainable development however critics have pointed out that although the capability approach takes the environment into account it has its shortcomings for not being a complete ethical theory our article attempts to go beyond these criticisms and show that the capabilities approach provides a good analytical framework for an environmental justice approach

critical ethical naturalism and the transformation of economics in this article i shall argue that critical ethical naturalism an ethical position elaborated by tony lawson can help understand lawson s critique of modern mainstream economics according to critical ethical naturalism human action should be concerned with removing obstacles that lie in the way of human development and flourishing the attempt of transforming economics into a discipline that contributes to human development rather than being an obstacle to such a development can be seen as an exercise driven by critical ethical naturalism albeit in a more implicit way in lawson s earlier writings and in a more explicit way in more recent writings but the significance of critical ethical naturalism as elaborated by lawson goes well beyond the problem of transforming economics and so i shall also highlight some more general implications of this ethical position before addressing the specific problem of transforming economics to do so i will first present lawson s critical ethical naturalism while showing the relevance of his social ontology for the study of ethics at various levels of generality including meta ethics ethical theory and applied ethics

a basis for sraffian ecological economics a comment on martins ecosystems strong sustainability and the classical circular economy martins 2016 recently emphasized the role that classical economics can play in building sustainability economics in this respect he uses sraffa s theory of value and sen and nussbaum s capability theory to support his argument my comment focuses on the part of his article concerning sraffa s theory and aims to refine some of martins claims in order to avoid misunderstandings about the possibilities offered by sraffa s theory

what price coordination the efficiency enhancing effect of auctioning the right to play a model is proposed to explain the results of recent experiments in which subjects repeatedly played a coordination game with the right to play auctioned each period in a larger group subjects bid the market clearing price to a level recoverable only in the efficient equilibrium and then converged to that equilibrium although subjects playing the game without auctions converged to inefficient equilibria the efficiency enhancing effect of auctions is reminiscent of forward induction but is not explained by equilibrium refinements the model explains it by showing how strategic uncertainty interacts with history dependent learning dynamics to determine equilibrium selection copyright 1998 by american economic association

factors explaining the low and variable profitability of fertilizer application to maize in zambia it is widely recognized that an african green revolution will require greater use of inorganic fertilizers often made comparisons note that fertilizer use rates in africa are just 10 20 of those in asia europe and the americas most attempts to explain relatively low adoption of fertilizer assume yield responses to inorganic fertilization warrant higher application rates and hypothesize that observed use rates are limited by market based factors another explanation may be that application rates are low because african yields are less responsive to inorganic fertilizer than yields in other regions and less responsive than analysts perceive examining the case of zambia we evaluate whether yield response to fertilizers could explain adoption and application rates a model of yield response is constructed and a combination of estimators is employed to mitigate potential biases related to correlation between fertilizer use and unobserved heterogeneity as well as stochastic shocks results indicate higher fertilization rates would be marginally profitable or unprofitable in many cases given commercial fertilizer and maize prices phosphoric fertilizer is particularly unprofitable on acidic soils which are common in zambia and other areas of sub saharan africa we propose feasible recommendations for diversifying the current government strategy to enhance crop productivity

ends in view the capabilities approach in ecological sustainability economics while traditional scientific endeavor seeks to avoid the problem ecological economics and the broader emergent field of sustainability economics e se are explicitly grounded in a particular ethico moral assertion one that defines sustainability as a normative notion about the way how humans should act towards nature and how they are responsible towards one another and future generations baumgartner and quaas 2010 p 445 thus e se is neither a purely positive science nor is it a purely normative endeavor but it is what has been called relevant science baumgartner and quaas 2010 p 447 a key objective of e se is therefore said to be to study how ecosystems and human activity interrelate in terms that extend beyond functional and descriptive analysis of this interrelationship and towards explicitly incorporating this normative vision the result that is aimed for is a discipline that is constituted as the best possible approach to the science and management of sustainability

the classical circular economy sraffian ecological economics and the capabilities approach abstract here i provide some further elaborations on the idea of a classical circular economy and its articulation with the capabilities approach this enables addressing some important questions raised by yoann verger 2017 when commenting on the idea of a classical circular economy as outlined in martins 2016 while advancing the basis for a sraffian ecological economics to understand the connections between sraffa s economic theory and the classical circular economy discussed by verger 2017 an essential aspect to be addressed here is sraffa s interpretation of the classical conception of the wage which can be fruitfully addressed in terms of the capabilities approach as suggested by vivian walsh 2000

asset markets as an equilibrium selection mechanism coordination failure game form auctions and tacit communication abstract in this paper we explore the possibility that asset markets provide a means of tacit communication which may allow subjects to coordinate on the payoff dominant equilibrium in an underlying coordination game we find that the existence of a market price for the right to play does communicate information about the equilibrium selection problem specifically behavior never converged to the efficient outcome when subjects were endowed with the right to participate but always converged to the efficient outcome when subjects purchased the right to participate journal of economic literature classification numbers c720 g120