the adoption of reduced tillage the role of human capital and other variables this paper presents a model of adoption behavior and explains differences econometrically in farmers decisions to adopt reduced tillage practices and in the efficiency of farmers adoption decisions the empirical results obtained from microdata show that the probability of adopting reduced tillage in corn enterprises differs widely across farms and depends on soil characteristics cropping systems and size of farming operation the results also show that farmers schooling enhances the efficiency of the adoption decision

sequential formation of coalitions in games with externalities and fixed payoff division this paper analyzes a sequential game of coalition formation when the division of the coalitional surplus is fixed and the payoffs are defined relative to the whole coalition structure gains from cooperation are represented by a valuation which maps coalition structures into payoff vectors i show that any core stable coalition structure can be attained as a stationary perfect equilibrium of the game if stationary perfect equilibria may fail to exist in general games a simple condition is provided under which they exist in symmetric games furthermore symmetric stationary perfect equilibria of symmetric games generate a coalition structure which is generically unique up to a permutation of the players a general method for the characterization of equilibria in symmetric games is proposed and applied to the formation of cartels in oligopolies and coalitions in symmetric majority games journal of economic literatureclassification numbers c78 c71 1996 academic press inc

search unemployment and the production of jobs the authors investigate the performance of the economy when search is required to find employment and when the duration of unemployment varies across sectors they assume that in one sector factor markets are frictionless while in the other se ctor idle factors of production must actively search each other out i n order to produce they focus on how well the economy allocates work ers across sectors and the conditions under which the factor mix with in a sector is correct the authors demonstrate that in equilibrium t he search sector is too small and its factor intensity is too asymmet ric copyright 1987 by royal economic society

learning about a new technology pineapple in ghana this paper investigates the role of social learning in the diffusion of a new agri cultural technology in ghana we use unique data on farmers communication patterns to define each individual s information neighborhood conditional on many potentially confounding variables we find evidence that farmers adjust their inputs to align with those of their information neighbors who were surpris ingly successful in previous periods the relationship of these input adjustments to experience further indicates the presence of social learning in addition applying the same method to input choices for another crop of known technol ogy correctly indicates an absence of social learning effects jel d83 013 033 q16

technology adoption under production uncertainty theory and application to irrigation technology we propose a theoretical framework to analyze the conditions under which a farmer facing production uncertainty due to a possible water shortage and incomplete information will adopt a more efficient irrigation technology a reduced form of this model is empirically estimated using a sample of 265 farms located in crete greece the empirical results suggest that farmers choose to adopt the new technology in order to hedge against production risk in addition we show that the farmer s human capital also plays a significant role in the decision to adopt modern more efficient irrigation equipment

information and the persistence of private order contract enforcement institutions an experimental analysis abstract we study an experimental market in which some sellers are prone to moral hazard and in which a private order contract enforcement institution exists that can mediate trade and prevent sellers from reneging on their contractual obligations using the institution to resolve the moral hazard problem is costly we demonstrate that in this market the utilization of the private order contract enforcement institution may make public and private market signals uninformative and inhibit learning we study whether this potential information externality can limit adaptation away from the private order institution when it is efficient to do so consistent with theory we find inefficient persistence when the institution is used but by contrast efficient adaptation in other situations providing information to individuals who are using the private order institution allows them to partially adapt

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

the economic impact of agricultural extension a review the history of economic development shows that few countries have achieved sustained economic growth without first or simultaneously developing their agricultural sector in most developing countries agriculture is the most important economic activity providing income employment and foreign exchange without an efficient agricultural sector a country is severely constrained in its ability to feed itself or import foreign products for domestic consumption and development rapid technological advances in agriculture have occurred since world war ii these advances have induced great changes in agricultural production and also highlighted the importance of a rapid and efficient transfer of advanced knowledge to the farmer when farmers become aware of the availability of new technology they may have inaccurate perceptions of the related costs and benefits as information availability may be limited as farmers decisions are based on their perceptions their resource allocation and technology choice will deviate from the social optimum if perceptions do not coincide with the correct attributes of the technology both society and the farmers as individuals would gain from improved information and theoretically there should exist a market for information however information on improved agricultural technology is often a public good because the provider of the information cannot exclude other potential users from free access to information provided to one user and the value of the information is not directly affected by the number of users while many instances of market activities in various aspects of agricultural information are observed e g specialized information on pest man

international environmental agreements the role of foresight the present paper attempts to bridge the gap between the cooperative and the non cooperative approach employed to examine the size of stable coalitions formed to address global environmental problems we do so by endowing countries with foresightedness that is by endogenizing the reaction of the coalition s members to a deviation by one member we assume that when a country contemplates withdrawing or joining an agreement it takes into account the reactions of other countries ignited by its own actions we identify conditions under which there always exists a unique set of farsighted stable ieas the new farsighted ieas can be much larger than those some of the previous models supported but are not always pareto efficient

a theory of endogenous coalition structures consider an environment with widespread externalities and suppose that bind ing agreements can be written we study coalition formation in such a setting our analysis proceeds by defining on a partition function an extensive form bargaining game we establish the existence of a stationary subgame perfect equilibrium for such a game our main results are concerned with the characterization of equilib rium coalition structures we develop an algorithm that generates under certain conditions an equilibrium coalition structure our characterization results are especially sharp for symmetric partition functions in particular we provide a uniqueness theorem and apply our results to a cournot oligopoly journal of economic literature classification numbers c71 c72 c78 d62 q 1999 academic press

trade unions and the efficiency of the natural rate of unemployment decentralized wage setting in search equilibrium models is inefficient because the meeting firm and worker ignore the dependence of job matching probabilities on the number of firms and workers engaged in search this paper investigates whether risk neutral monopolistic unions will have an incentive to internalize this externality i find that the externality will be internalized only if the union s policy is chosen by unemployed persons if employed persons influence union policy both the union wage and unemployment will be too high a tax on the union wage combined with an employment subsidy to firms can correct this inefficiency

farsighted coalitional stability abstract i define the largest consistent set a solution concept which applies to situations in which coalitions freely form but cannot make binding contracts act publicly and are fully farsighted in that a coalition considers the possibility that once it acts another coalition might react a third coalition might in turn react and so on without limit i establish weak nonemptiness conditions and apply it to strategic and coalitional form games and majority rule voting i argue that it improves on the von neumann morgenstern stable set as it is usually defined but is consistent with a generalization of the stable set as in the theory of social situations journal of economic literature classification numbers c70 c71

peer effects and the choice of adaptation strategies this paper analyzes the impact of peer choices on the decision to adapt to climate change in rural ethiopia two ivs are employed peer of peer choices and peer of peer information sources in order to tackle the issue of endogeneity through the use of a 3 year panel of farmers in the nile basin region we find that peer choices positively affect the uptake of different adaptation strategies a 10 percentage point increase in the share of peers using a specific strategy translates to an increase in the likelihood of adaptation between approximately 7 and 14 this emphasizes the importance of social networks to achieve adaptation to climate change in sub saharan africa

history s role in coordinating decentralized allocation decisions what causes individual suppliers to allocate goods in such a way that the aggregate allocation satisfies the law of one price a satisfactory answer to this question must confront two related problems equal net prices at all allocations provide no information to suppliers about the quantity to deliver to a specific location and strategic uncertainty makes an observed violation of the law of one price an unreliable indicator of a profit opportunity this paper develops a simple analytical framework to formalize these two problems reviews some solutions found in the literature and reports laboratory evidence on how people solve them in addressing these issues we focus on the role historical prices play in coordinating decentralized allocation decisions

the citizen candidate model an experimental analysis citizen candidate models represent a significant advance in the analysis of public choice they provide added realism to models of endogenous policy formation relate the number of candidates to the benefits and costs associated with electoral competition and support equilibria with differentiated candidate positions even with a multidimensional policy space in this paper experimental methods are utilized to test two of the model s equilibrium predictions the results support the prediction that an increase in the net benefits to winning an election increases the number of citizens entering electoral contests when the net benefits to winning an election are low the results support the prediction that the only candidate has the median preference further the results suggest that when net benefits are high two members of the electorate with preferences close to and symmetric about the median enter the election although convergence to this equilibrium takes time because entry is costly having multiple candidates lowers group payoffs and may be seen as inefficient

equilibrium binding agreements abstract we study equilibrium binding agreements the coalition structures that form under such agreements and the efficiency of the outcomes that result we analyze such agreements in a context where the payoff to each player depends on the actions of all other players thus a game in strategic form is a natural starting point unlike the device of a characteristic function explicit attention is paid to the behavior of the complementary set of players when a coalition blocks a proposed agreement a solution concept and its applications are discussed journal of economic literature classification numbers c70 c71

learning by doing and learning from others human capital and technical change in agriculture household level panel data from a nationally representative sample of rural indian households describing the adoption and profitability of high yielding seed varieties hyvs associated with the green revolution are used to test the implications of a model incorporating learning by doing and learning spillovers the estimates indicate that i imperfect knowledge about the management of the new seeds was a significant barrier to adoption ii this barrier diminished as farmer experience with the new technologies increased iii own experience and neighbors experience with hyvs significantly increased hyv profitability and iv farmers do not fully incorporate the village returns to learning in making adoption decisions

modeling technology adoption in developing countries an analysis of technology adoption decisions by poor farmers is provided some possible empirical models for studying technology adoption are reviewed the issue of theoretical consistency is dealt with in terms of the costs of such consistency measured in data needs and model complexity and the benefits measured in terms of understanding the micro economic foundations of adoption

unemployment insurance and redistributive taxation abstract this paper studies the simultaneous determination of the socially optimal levels of unemployment insurance income taxation and experience rating it argues that there is a normative justification for state unemployment insurance when the government wishes to use redistributive taxes but cannot enforce lump sum transfers it is not socially optimal for there to be full experience rating of unemployment insurance schemes one distortion should be used to off set another the state must then intervene in the provision of insurance for those without jobs

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

impact of conservation agriculture technology on household welfare in zambia this article examines the determinants and impact of conservation agriculture ca technology adoption on farm household welfare in zambia to account for selection bias from both observable and unobservable factors an endogenous switching regression model is employed to estimate the impact of the technology on continuous outcomes like farm output throughput accounting ratio tar poverty gap and severity of poverty a recursive bivariate probit model is however used for the estimation of impact of adoption on a binary outcome like poverty headcount the empirical findings demonstrate that the adoption of ca technology increases maize output and farm tar and reduces household poverty moreover the results reveal that farmers years of schooling social networks access to credit extension services and machinery as well as soil quality positively influence adoption of ca technology

econometric estimation of producers risk attitudes general methods are proposed for the identification and econometric estimation of the parameters of the distribution of risk attitudes in a producer population the proposed methods also provide the basis for the development of statistical tests of model specification and of behavioral hypotheses econometric risk attitude estimation is shown to be possible under less restrictive conditions than previously believed a moment based version of the general model is applied to indian data and the econometrically estimated risk attitudes are presented and compared to experimental results for a similar group of producers

coalitions agreements and efficiency if agents negotiate openly and form coalitions can they reach efficient agreements we address this issue within a class of coalition formation games with externalities where agents preferences depend solely on the coalition structures they are associated with we derive ray and vohra s 1997 notion of equilibrium binding agreements using von neumann and morgenstern abstract stable set and then extend it to allow for arbitrary coalitional deviations as opposed to nested deviations assumed originally we show that while the new notion facilitates the attainment of efficient agreements inefficient agreements can nevertheless arise

irrigation technology adoption and gains from water trading under asymmetric information we develop a water allocation and irrigation technology adoption model under the prior appropriation doctrine with asymmetric information among heterogeneous farmers and between farmers and water authorities we find that adverse selection reduces the adoption of modern irrigation technology we also show that even with asymmetric information incentives for water trade exist and lead to additional technology adoption with gains to all parties this suggests that under asymmetric information a thin secondary market improves the allocation of water resources and induces additional adoption of modern irrigation technologies

coordination matching and wages we analyse the coordination problem in the labour market by endogenizing the matching function and the wage share each firm posts a wage to maximize the expected profit anticipating how the wage affects the expected number of applicants in equilibrium workers apply to firms with mixed strategies which generate coordination failure and persistent unemployment we show how the wage share unemployment and the welfare loss from the coordination failure depend on the market tightness and the market size the welfare loss from the coordination failure is as high as 7 5 per cent of potential output jel classification c78 j64 les auteurs analysent le probleme de la coordination dans le marche du travail en endogeneisant la fonction arrimage et la part des revenus qui va aux salaires chaque entreprise definit le niveau de salaire qui maximise ses profits anticipes en tenant compte de l effet de ce niveau de salaire sur le nombre des applications qu elle peut anticiper de meme les travailleurs font application aupres d une entreprise a un salaire donne en tenant compte d une certaine relation d equivalence entre niveau de salaire et probabilite d obtenir l emploi voila qui engendre incoordination et chomage persistant on montre que la part des revenus qui revient aux salaires le niveau de chomage et les pertes de bien etre attribuables au manque de coordination dependent de la taille du marche et du degre de rarete de la main d oeuvre les pertes de bien etre attribuables au manque de coordination correspondent a quelques 7 5 pour cent de la production potentielle

job matching when employment contracts suffer from moral hazard abstract we consider a job matching model where the relationships between firms and wealth constrained workers suffer from moral hazard specifically effort on the job is non contractible so that parties that are matched negotiate a bonus contract higher unemployment benefits affect the workers outside option the latter is improved for low skilled workers hence they receive a larger share of the surplus which strengthens their effort incentives and increases productivity effects are reversed for high skilled workers moreover raising benefit payments affects the proportion of successful matches which induces some firms to exit the economy and causes unemployment to increase

an explanation of anomalous behavior in models of political participation this paper characterizes behavior with noisy decision making for models of political interaction characterized by simultaneous binary decisions applications include voting participation games candidate entry the volunteer s dilemma and collective action problems with a contribution threshold a simple graphical device is used to derive comparative statics and other theoretical properties of a quantal response equilibrium and the resulting predictions are compared with nash equilibria that arise in the limiting case of no noise many anomalous data patterns in laboratory experiments based on these games can be explained in this manner

revenue equivalence revisited the conventional wisdom in the auction design literature is that first price sealed bid auctions tend to make more money while ascending auctions tend to be more efficient we re examine these issues in an environment in which bidders are allowed to endogenously choose in which auction format to participate our findings are that more bidders choose to enter the ascending auction than the first price sealed bid auction and this extra entry is enough to make up the revenue difference between the formats consequently we find that both formats raise approximately the same amount of revenue they also generate efficiency levels and bidder earnings that are roughly equivalent across mechanisms though the earnings in the ascending might be slightly higher

a dynamic model of bertrand competition with entry abstract this paper analyzes a simple repeated game of simultaneous entry and pricing we report a surprising property of the symmetric equilibrium solution if the number of potential competitors is increased above two the market breaks down with higher probability and the competitive outcome becomes less likely more potential competition lowers welfare another bertrand paradox the model can also be applied to auctions to explore whether a revenue maximizing auctioneer should restrict the number of bidders if bidder participation is costly

the assignment of workers to jobs in an economy with coordination frictions this paper studies the assignment of heterogeneous workers to heterogeneous jobs owing to the anonymity of a large labor market workers use mixed strategies when applying for jobs this randomness generates coordination frictions two workers may apply for a particular job whereas an identical job gets no applications the model generates assortative matching with a positive but imperfect correlation between matched workers and firms types it predicts that a worker s wage is increasing in her job s productivity and a firm s profit is increasing in its employees productivity the model also yields a version of the welfare theorems

identification of endogenous social effects the reflection problem this paper examines the reflection problem that arises when a researcher observing the distribution of behaviour in a population tries to infer whether the average behaviour in some group influences the behaviour of the individuals that comprise the group it is found that inference is not possible unless the researcher has prior information specifying the compisition of reference groups if this information is available the prospects for inference depend critically on the population relationship between the variables defining reference groups and those directly affecting outcomes inference is difficult to implossible if these variables are functionally dependent or are statistically independent the prospects are better if the variables defining reference groups and those directly affecting outcomes are moderately related in the population

synergy and learning effects of informal labor sharing arrangements summary we study the effects of informal labor sharing arrangements and other social interactions on farmers productivity in a developing country context testing whether these types of social and work interactions lead to productivity gains through learning synergy or both using a rich panel data set of ethiopian subsistence farmers we estimate a distance function of grains production and find large productivity gains approximately 33 and 29 in 1999 and 2004 from labor sharing due to synergy effects that boost labor productivity however labor sharing does not lead to learning as the productivity gains observed in years with labor sharing disappear in following years if the farmers do not continue to engage in labor sharing labor sharing partners are either neighbors relatives members of the same funeral and religious associations or have plots next to each other which together reduce labor sharing as a single venue for learning however the synergy effect is strong enough to warrant the design of extension and outreach policies that recognize and utilize farmers informal social networks such as labor sharing arrangements

the diffusion of new agricultural technologies the case of crossbred cow technology in tanzania the recent literature on agricultural technology adoption shows that diffusion of new technologies varies significantly across space and time furthermore puzzles exist about why some seemingly profitable technologies are not adopted especially in livestock production we employ a hazard or duration function to explain diffusion of crossbred cow technology in a unique sample of tanzania farmers a farmer s adoption of crossbred technology depends positively on the proximity of his farm to other users on his schooling and on his access to credit and contact with extension agents

mobility costs frictional unemployment and efficiency with imperfect job information flows it is plausible that the distribution of job offerings becomes more attractive when there are more vacancies and more unemployed with word of mouth communication this condition is derived given this condition steady state equilibrium is not efficient with welfare increased by the introduction of unemployment compensation even though all agents are risk neutral in this way workers become more selective in the jobs they accept

the stability of hedonic coalition structures we consider the partitioning of a society into coalitions in purely hedonic settings i e where each player s payoff is completely determined by the identity of other members of her coalition we first discuss how hedonic and nonhedonic settings differ and some sufficient conditions for the existence of core stable coalition partitions in hedonic settings we then focus on a weaker stability condition individual stability where no player can benefit from moving to another coalition while not hurting the members of that new coalition we show that if coalitions can be ordered according to some characteristic over which players have single peaked preferences or where players have symmetric and additively separable preferences then there exists an individually stable coalition partition examples show that without these conditions individually stable coalition partitions may not exist we also discuss some other stability concepts and the incompatibility of stability with other normative properties journal of economic literature classification numbers c71 a14 d20

learning with fixed rules the minority game abstract this paper gives a critical account of the literature on adaptive behaviour in the minority game a simple congestion game the literature has proposed a model which differs markedly from many standard learning models in that players are endowed with a fixed subset of behavioural rules or response modes which map the observed history to actions these rules need not have a behavioural interpretation or be derived from some form of optimizing behaviour nonetheless this model gives rise to behaviour that is close to equilibrium behaviour at the aggregate level the individual level behaviour predicted by the model seems to capture some aspects of observed experimental behaviour that are difficult to explain using standard models

information transmission in irrigation technology adoption and diffusion social learning extension services and spatial effects in this article we investigate the role of information transmission in promoting agricultural technology adoption and diffusion through extension services and social learning we develop a theoretical model of technology adoption and diffusion which we then empirically apply using duration analysis on a micro dataset consisting of recall data covering the period 1994 2004 for olive producing farms from crete greece our findings suggest that both extension services and social learning are strong determinants of technology adoption and diffusion while the effectiveness of each of the two informational channels is enhanced by the presence of the other

social learning and technology adoption the case of coffee pruning in peru a unique natural experiment involving a coffee pruning technology is used to study social learning the yield effects of pruning take two years to appear a characteristic that aids in identifying social learning apart from correlated unobservable variables that are a concern in the social learning and technology adoption literature panel data are employed that start with a private initiative which introduced systematic pruning in central peru and that contain the population of participating growers results show a jump of at least 0 15 in the probability of adoption two years after the first pruning in a grower s group jel classifications d83 q12

the story of the moment risk averse cypriot farmers respond to drought management this article illustrates the importance of estimating risk preferences when evaluating water policy using agricultural production data from the kiti region of cyprus we estimate farmers risk preferences a la antle journal of business and economic statistics 1 192 201 1983 american journal of agricultural economics 69 509 22 1987 and show sensitivity to higher order moments of profit such as skewness we show that farmers in the kiti region are risk averse with risk premiums in the region of 20 of expected profit we use these estimates to analyse the impact of a water quota from the perspective of three policy makers who differ only in their understanding of farmers risk preferences we show in the case of kiti that policy makers who model risk preferences incorrectly that is either a assume risk neutrality or b ignore down side risk wrongly predict the magnitude and direction of input responses and therefore the magnitude of welfare changes this highlights the importance of accomm

stable coalition structures with externalities this paper argues that the sign of external effects of coalition formation provides a useful organizing principle in examining economic coalitions in many interesting economic games coalition formation creates either negatie externalities or posi tie externalities for nonmembers examples of negative externalities are research coalitions and customs unions examples of positive externalities include output cartels and public goods coalitions i characterize and compare stable coalition structures under the following three rules of coalition formation the open