technology adoption under seed access constraints and the economic impacts of improved pigeonpea varieties in tanzania dry land legumes well adapted to drought prone areas have largely been neglected in the past despite the good opportunities they offer for income growth and food and nutritional security for the poor this study evaluated the adoption and impact of two farmer and market preferred and disease resistant pigeonpea varieties that were developed and promoted in semi arid tanzania the new varieties were resistant to fusarium wilt a fungal disease devastating the crop however farmers wanting to adopt new varieties did not adopt due to seed access constraints and under developed seed delivery systems adoption of new varieties is therefore analyzed using an augmented double hurdle model that allows estimating variety adoption conditional on seed access thresholds accounting for the additional information on sample separation the study identifies the crucial role of seed access local supply extension education participatory decision making capital and household assets in determining adoption the social economic benefits of the technology and policies for improved seed access were further analyzed using the extended economic surplus method dream model even under restrictive assumptions overall discounted benefits were found to be quite attractive indicating the need for additional efforts to scale up the success story analysis of changes in research benefits from relaxing the seed access constraint showed that net gains would increase by up to 30 if farmer access to improved seeds can be assured smallholder farmers are the major beneficiaries along with consumers and rural net buyers who gain from productivity induced lower market prices

consistent solutions in atomless economies we consider the problem of allocating a bundle of commodities among a group of agents who are collectively entitled to them we prove for an atomless economy with possibly satiated preferences any solution that is efficient equitable and consistent must select allocations that are supported by equal budget walrasian equilibria with slack we consider the problem of allocating a bundle of commodities among a group of agents who are collectively entitled to them we search for systematic methods or solutions of resolving this problem for a solution to be considered desirable we propose that it should satisfy several requirements first it should be efficient second it should be equitable a variety of distributional require ments have been proposed in the literature the requirement we will impose here is that it select allocations at which no agent would prefer the equal division of the social endowment to his own consumption in addition to these two basic efficiency and equity conditions we require that the solution be consistent the recommendations it makes for any economy are never contra dicted by the recommendations it makes for any reduced economy obtained by allowing some subgroup of agents to leave the scene with their allotted consumptions the requirement of consistency is very natural here is a motivation for it offered by thomson 1988 consider all the resources available on the planet earth one would like not only that they be distributed fairly when the planet is considered as a whole but also that whatever resources end up in each continent country city be fairly distributed among the members of that subpopulation when considered in isolation in this paper we study economies with a large number of agents modelled as a complete atomless measure space our main result is a characterization of the solutions that satisfy all three requirements of efficiency equity and con sistency it follows from our result that under standard assumptions on preferences any such solution must select allocations that are supported by equal income walrasian equilibria however our characterization holds for more general economies since it applies to economies in which preferences are possibly satiated mas colell 1988 extended traditional general equilibrium theory to the class of such economies by introducing the notion of walrasian

the potential for agricultural trade among eastern and southern african countries abstract this study investigates the potential for expanding trade in grains and cereals among the countries of eastern and southern africa in the absence of measures of comparative costs and disaggregated bilateral data the method was to determine whether the consumption and production characteristics of the countries imply that trade is below its potential the countries demonstrate characteristics consistent with greater trade in grains and cereals than occurs the region is not a chronic importer of grains except in years of severe drought greater intra regional trade in grains is implied by the significantly different structures of consumption and production across countries these differences suggest that greater grain self sufficiency for each country taken separately might not be efficient but it could be for the region as a whole along with the evidence for differences in consumption and production patterns goes statistical support for the likelihood that the countries could absorb each other s surpluses and fill each other s shortages over time

approaches to the privatization of fertilizer marketing in africa abstract agricultural marketing privatization has been a central feature of structural adjustment recommendations this paper briefly analyses the main issues related to privatization in the fertilizer sector in africa reviews developments and examines possible reasons for the relatively slow progress to date constraints to effective privatization are identified and policy changes and other reforms necessary if fertilizer marketing privatization is to succeed are proposed effective privatization will not be achieved without detailed planning and consideration of potential problems at an early stage

policies for african seed enterprise development abstract the commercial seed sector has been slow to develop in sub saharan africa the paper examines the major impediments and identifies areas in which seed policies can be strengthened seed enterprise development has been hampered by regulatory frameworks that favor parastatal enterprises and that inhibit commercial innovation in addition government and donor projects provide large amounts of free or subsidized seed that further discourages seed enterprise development in addition to regulatory reform and the curtailment of many seed distribution projects there are other policy changes that need to be implemented national agricultural research institutes need to invest more resources in promoting their varieties and helping to stimulate commercial seed production greater emphasis is required on regional strategies for public plant breeding and private seed marketing national policies need to strengthen input marketing capacity and infrastructure finally donors governments and ngos should shift from trying to encourage village level commercial seed production and instead strengthen farmers capacities to assess new varieties and to be effective consumers of commercial inputs

the competitive allocation process is informationally efficient uniquely abstract this paper establishes that the competitive allocation process is the only informationally decentralized mechanism for exchange environments which i achieves pareto optimal allocations ii gives each consumer an allocation which is according to his preferences at least as good as his endowment iii satisfies certain regularity conditions and iv has a message space of the smallest dimension necessary to satisfy i iii

on characterizing optimal competitive programs in terms of decentralizable conditions the paper considers a multisector model of intertemporal allocation with a primary factor of production and the overtaking criterion of optimality the optimal program is characterized in terms of i period by period conditions on intertemporal profit and utility maximization relative to a system of competitive prices and ii non positivity of appropriately computed values of differences of stocks from the golden rule stock the last condition replaces the usual transversality condition of malinvaud and throws new light on the possibility of dencentralization in an infinite horizon economy

can the public sector meet the challenge of private research commentary on falcon and fowler and pingali and traxler abstract the growth of private sector participation in agricultural research has serious implications for pro poor technology development but there are other factors that must be considered new plant varieties are not the only things standing between resource poor farmers and secure livelihoods and institutional strengthening is also necessary in addition the current state of public agricultural research is cause for concern it is not clear how many effective public private partnerships can be formed the public sector needs a much clearer definition of its targets and priorities and funding strategies for national and international agricultural research must be overhauled

optimal intertemporal allocation mechanisms and decentralization of decisions abstract problems of achieving an efficient or optimal allocation of resources through a system of decentralized decision making when the planning horizon is unbounded and the number of agents is infinite have been repeatedly raised but have not been explored in a formal manner the objective of this paper is to suggest some points of departure for a systematic investigation of such questions the main analytical results indicate the impossibility of attaining optimality through intertemporally decentralized mechanisms

implementation in economies with a continuum of agents we study a general implementation problem for exchange economies with a continuum of players and private information and test the robustness of the results for sequences of approximating finite economies assuming that the designer knows the distribution of the characteristics in the economy we consider continuous and unique implementation in both its equilibrium and dominant strategies versions and obtain results for general self selective first and second best allocations an upper hemicontinuity property of bayesian equilibria of approximating economies for continuous mechanisms is demonstrated using this we can for example conclude that if a given continuous mechanism implements uniquely a walrasian allocation in the continuum economy then all bayesian equilibria of large approximation economies will with probability close to one yield an allocation which is almost ex post pareto optimal

sanctions on south africa what did they do this paper considers the economic sanctions that were applied in the mid 1980s to pressure the south african government to end apartheid it asks what role those sanctions played in the eventual demise of the apartheid regime and concludes that the role was probably very small an alternative explanation for the regime change is offered the communist bloc combined to bring about the change if one is to argue for the efficacy of sanctions two key obstacles are their limited economic impact and the substantial lag between the imposition of sanctions and the political change since sanctions preceded the change of government it is impossible to rule them out as a determinant however their principal effect was probably psychological the implication is that the south african case should not serve as the lone major instance of effective sanctions this abstract was borrowed from another version of this item

seed regulation choices on the road to reform major changes in national seed systems including the rapid development of commercial seed enterprises the growth of non governmental organization ngo seed projects and the concomitant decline of public sector seed provision call for a re examination of seed regulatory frameworks in developing countries privatization and deregulation are often presented as logical partners but the nature of seed system change and the complexities of regulatory responsibility make seed regulatory reform less straightforward than it first appears challenges include the limited opportunities for commercial seed development the need to provide guidance to seed systems in transition the international pressures for plant variety protection pvp and significant differences among various national regulatory approaches problems with the conduct of current seed regulations include significant inefficiency the use of inappropriate standards inadequate opportunities for the participation of new entrants to the seed system and a lack of transparency specific guidelines are offered for reorganizing variety registration and performance testing providing a balanced opportunity for pvp and broadening participation in seed quality control national seed regulatory agencies will see their role shift from the direct supervision of seed production towards technical and policy support for the development of a wider range of seed provision options

a necessary condition for decentralization and an application to intertemporal allocation abstract a necessary condition for realization by a decentralized finite dimensional mechanism is proved the concepts of the realization of a time sequence of allocations by a decentralized temporal process and by the particular more realistic class of decentralized evolutionary temporal processes are defined the above condition shows that the optimal allocation in a simple model for intertemporal production and consumption can be realized by a decentralized temporal process but not by a decentralized evolutionary process which uses either a finite number of verification conditions or a finite dimensional message space

ngos and seed provision to smallholders in developing countries abstract public sector provision of improved seeds in developing countries has often fallen foul of government failure while commercial seed supply has faced unusually high transactions costs and some market failure both have met difficulties in providing appropriate seed for marginal farm lands into the gap have come nongovernmental organisations ngos most of them involved in small scale seed multiplication and distribution evidence from a review of 19 ngo programs suggests that their seed activities operate on a small scale sometimes with little distinctive technical competence and tend to ape other formal sector methods above all they face a challenge in making their efforts sustainable the most promising avenue seems to lie in their supporting the growth of small seed production and distribution enterprises at farm and village level

anarchy and its breakdown anarchy defined as a system in which participants can seize and defend resources without regulation from above is not chaos but rather a spontaneous order however anarchy is fragile and may dissolve either into formless amorphy or into a more organized system such as hierarchy under anarchy each contestant balances between productive exploitation of the current resource base and fighting to acquire or defend resources anarchy is sustainable only when there are strongly diminishing returns to fighting effort the decisiveness parameter is sufficiently low and incomes exceed the viability minimum these considerations explain many features of animal and human conflict

a unique informationally efficient allocation mechanism in economies with consumption externalities this article investigates the informational requirements of resource allocation processes in pure exchange economies with consumption externalities it is shown that the distributive lindahl mechanism has a minimal informational size of the message space and thus it is informationally the most efficient allocation process that is informationally decentralized and realizes pareto efficient allocations over the class of economies that include nonmalevolent economies furthermore it is shown that the distributive lindahl mechanism is the unique informationally efficient decentralized mechanism that realizes pareto efficient and individually rational allocations over a certain class of nonmalevolent economies

can public private partnerships leverage private investment in agricultural value chains in africa a preliminary review summary public private partnerships ppps may be one way of increasing the level of private sector investment into poorly performing agricultural value chains this paper considers a range of ppp mechanisms that respond to different market failures affecting such chains and draws on principal agent theory to illustrate the challenges it reviews emerging experience with a number of these mechanisms along with experience from other sectors that may shed light on generic problems of implementing ppps in africa while finding some positive impacts on investment it notes that state failures can also undermine ppp effectiveness as the evidence base is still limited it calls on organizations promoting innovative ppps to disclose available information for critical examination

von stackelberg and cournot duopoly choosing roles under what circumstances will firms agree on the choice of roles of leader and follower in the von stackelberg duopoly model a key determinant is the slope of the firms reaction function in either price or quantity space the duopolists will disagree over the choice of roles if they have downward sloping reaction functions each will prefer to be the leader they will also disagree if they have upward sloping reaction functions and similar profit functions each will prefer that the other be the leader preferences between von stackelberg and cournot outcomes are also considered

characterization of intertemporal optimality in terms of decentralizable conditions the discounted case abstract the paper studies the problem of characterizing the optimality of competitive programs in terms of decentralizable conditions we show that when future utilities are discounted and the optimal stationary stock is proportionately expansible then optimality of competitive programs can be characterized by the condition that the scalar product of the difference of prices and quantities between those of the given competitive program and those of the optimal stationary program be non positive period by period

theocracy and resilience against economic sanctions abstract this paper provides a simply theory to explain the impact of sanctions on a regime s policies and behavior sanctions are generally put to strip the target country from its available rents and weaken the government s stance against growing discontent in the population we show however that sanctions may give legitimacy to an incumbent government by influencing the optimal level of religious ideology provided by the state and further stabilizing its grip to power and rents while in a good state of nature sanctions build resilience as long as religious ideology among the population is strong at bad times they compel the target country to move towards ideological moderation in a world of asymmetric information the target country always finds it optimal to send a signal that truly represents the prevailing state of nature in order to induce learning and reach a win win outcome

the genealogy of modern theoretical public economics from first best to second best abstract the development of second best modelling in the seventies has shaped modern theoretical economics the paper discusses some key changes in the economists conceptions the first two sections examine the efficiency equity dilemma the study of non convexities has shown that counterintuitive efficiency enhancing income redistribution might occur the introduction of asymmetric information has shed doubts on virtues of lump sum compensation the last sections focus on the intricate geometry of second best optimisation and the ambiguous value of the signals provided by the price system outside a first best world

sanctions some simple analytics governments often seek influence beyond their borders one way is through what thomas schelling 1960 1966 calls brute force taking direct physical control less extreme methods are to promise rewards for taking desired actions or to threaten punishments for not carrying them out sanctions sanctions involve two parties the sender and the target to help identify pronouns antecedents we consider a feminine sender and masculine target the sender s objective is to influence the target by threatening to impose some measure against him for acting contrary to her interest sanctions have long been important in international relations athens imposed a trade embargo against megara ultimately setting off the peloponnesian war 431 404 bc sanctions are central to such international agreements as the united nations charter the world trade organization and the montreal protocol governing chlorofluorocarbons u s law prescribes the use of sanctions in circumstances related for example to national security human rights intellectual property and international trade do sanctions actually achieve senders objectives a common claim is that they usually fail and are costly to senders recent u s legislation proposes to limit unilateral u s sanctions except trade related ones on the grounds that they cost more than they are worth history provides examples of sanctions that were costly and ineffectual such as the league of nations sanctions against the italian occupation of abyssinia or u s sanctions against cuba united nations sanctions against iraq remain in place having achieved less than full success to say the least see gary hufbauer et al 1990 more systematic studies suggest that sanctions often do succeed particularly when objectives are modest hufbauer et al 1990 examine 116 episodes of sanctions with military or political objectives deeming about one third successful sanctions imposed under u s trade law have worked even better about three fourths of the time see e g sykes 1992 thomas bayard and kimberly a elliott 1994 elliott and j david richardson 1997 here we develop a simple framework to explain how sanctions can worl and what is required for them to succeed our framework exploits advances in the theory of repeated games and bargaining under incomplete information while a game theorist would recognize the flavor of our results the setting here is a fresh one 2 we find success more likely when the threatened measure costs the sender little relative to the gain from modifying the target s behavior while the damage to the target is large relative to his cost of complying with the sender s will results consistent with both intuition and empirical evidence as well as with adam smith 1776 book iv ch i moreover a more patient sender is more likely to succeed while the target s patience can work to the sender s disadvantage 3

implementation of balanced linear cost share equilibrium solution in nash and strong nash equilibria abstract this paper considers the incentive aspect of the balanced linear cost share equilibrium blcse which yields an endogenous theory of profit distribution for public goods economies with convex production technologies we do so by presenting an incentive compatible mechanism which doubly implements the blcse solution in nash and strong nash equilibria so that nash allocations and strong nash allocations coincide with blcse allocations the mechanism presented here allows not only preferences and initial endowments but also coalition patterns to be privately observed in addition it works not only for three or more agents but also for two agent economies

efficient incentive compatible economies are perfectly competitive abstract efficient anonymous and continuous mechanisms for exchange environments with a finite number of individuals are dominant strategy incentive compatible if and only if they are perfectly competitive i e each individual is unable to influence prices or anyone s wealth equivalently in such a mechanism each individual creates no externalities for others by her announcement of a type the characterization applies whether preferences are ordinal or quasilinear and it also applies to continuum economies perfectly competitive mechanisms are non generic although non vacuous in finite economies and are generic but non universal in continuum economies we use these results to provide bridges to related work journal of economic literatureclassification numbers c72 d51 d62

on characterizing optimality of stochastic competitive processes abstract a condition is provided to replace the transversality condition in characterizing the optimality of competitive processes this extends the work of w brock l hurwicz and m majumdar on characterizing optimality of competitive programs in terms of decentralizable conditions and optimal intertemporal allocation mechanisms and decentralization of decisions cornell university working paper nos 333 and 369 1985 on providing an informationally decentralizable condition for characterizing optimality in stochastic infinite horizon models without discounting

envy freeness and distributive justice the criterion of envy freeness according to which no agent should prefer any of his neighbours allocation to his own has become a central part of the economic theory of distributive justice it essentially corresponds to the need to express an ideal of equality in societies where preferences and endowments are heterogeneous this paper surveys various formulations of the idea of envy freeness starting with the simple distribution model then adding the possibility for agents to have different native talent endowments and finally moving to models with production many classical results are displayed but emphasis is also put on recent developments mainly the ideas of minimizing envy and of absence of domination five major difficulties facing envy freeness are identified and listed as directions of future research copyright 1994 by blackwell publishers ltd

equilibrium and optimality some imprints of david gale abstract the paper is a review of some of the themes to which david gale made lasting contributions it touches upon a number of the fundamental issues in the walrasian equilibrium theory existence uniqueness and stability the overlapping generations model non optimality and indeterminacy of competitive equilibria the von neumann equilibrium as a turnpike and in the theory of decentralized intertemporal allocation through competitive prices efficiency and golden rules duality and existence of optimal programs

decentralization in infinite horizon economies an introduction abstract the paper summarizes some issues involved in developing a theory of decentralized resource allocation mechanism in infinite horizon economies even in a classical environment a competitive mechanism may lead to an inefficient or nonoptimal allocation for an infinite horizon economy it remains however to explore whether the usual price quantity messages can be supplemented to design decentralized mechanisms generating optimal outcomes

a sequential game of endowment effect and natural property rights abstract this study develops a sequential game between the incumbent and the intruder to examine how endowment effect decides natural property rights of a territory without third party intervention

on the existence of a stationary optimal stock for a multi sector economy a primal approach abstract using a purely primal approach we show the existence of a non trivial stationary optimal stock for a multi sector economy our result generalizes earlier work by dropping the productivity assumption and by replacing the continuity hypothesis on the utility function by upper semicontinuity

the communication requirements of social choice rules and supporting budget sets the paper examines the communication requirements of social choice rules when the sincere agents privately know their preferences it shows that for a large class of choice rules any minimally informative way to verify that a given alternative is in the choice rule is by verifying a budget equilibrium i e that the alternative is optimal to each agent within a budget set given to him therefore any communication mechanism realizing the choice rule must find a supporting budget equilibrium we characterize the class of choice rules that have this property furthermore for any rule from the class we characterize the minimally informative messages budget equilibria verifying it this characterization is used to identify the amount of communication needed to realize a choice rule measured with the number of transmitted bits or real variables applications include efficiency in convex economies exact or approximate surplus maximization in combinatorial auctions the core in indivisible good economies and stable many to one matchings

a note on incentives in large economies nash equilibria of anonymous and efficient mechanisms are studied in economies with a continuum of traders conditions are given under which some or all the nash equilibria of such mechanisms yield competitive allocations particular attention is payed to the case of direct mechanisms where the truth constitutes a nash equilibrium

welfare bounds in the fair division problem to any anonymous division method corresponds a lower and an upper bound function they measure the impact on a given agent s utility of the other agents preferences the highest lower bound is the equal split utility the lowest upper bound is the indirect utility from equal split at a canonical price these two bounds are compatible yet any method with the elqual split lower bound exhibits the growth paradox and any method with the lowest upper bound generates envy we criticize competitive equilibrium from equal split because it puts no finite upper bound on any agent s welfare

a unique informationally efficient and decentralized mechanism with fair outcomes it is shown that any informationally decentralized mechanism that realizes fair allocations over the class of classical pure exchange environments has a message space of dimension no smaller than the number of agents times the number of commodities since the equal income walrasian mechanism in which all agents take prices parametrically and maximize utility subject to the average income constraint realizes fair outcomes over the class of classical pure exchange environments and has a message space of that dimension it is informationally efficient further it is shown that it is the unique informationally efficient mechanism realizing fair allocations

implementation of the lindahl correspondence by a single valued feasible and continuous mechanism this paper considers the problem of designing mechanisms whose nash allocations coincide with the lindahl allocations for public goods economies with more than one private good unlike previous mechanisms the mechanism presented here has a single valued feasible and continuous outcome function furthermore when there are no public goods in economies feasible and continuous implementation of the constrained walrasian correspondence can be obtained as a corollary of our theorem 1

sanctions and civil conflict using a formal general equilibrium framework this paper analyses how sanctions imposed on the contestants in civil conflict affect the welfare of these contestants and the allocation of resources to conflict it is shown that weak sanctions can hurt the contestant they are supposed to help while strong sanctions augment the expected welfare of their intended beneficiaries moreover sanctions are more likely to be successful if the contestant who is subject to sanctions can expect to derive a positive income in case of compliance the likelihood of success rises as this income increases

an exact discount factor restriction for period three cycles in dynamic optimization models consider a standard aggregative dynamic optimization framework u where is the transition possibility technology set u is a reduced form utility function defined on this set and 0 1 a discount factor can an optimal program in this framework exhibit a period three cycle

the theory of international economic sanctions a public choice approach comment william kaempfer and anton lowenberg in this review september 1988 have developed an engaging model of the sanctions process grounded in public choice they identify potentially influential private forces that might affect the nature of a sanctions package while the spirit of their effort is laudable the model fails to incorporate some absolutely essential information about the legal institutional and strategic framework in which sanctions decisions are made as a consequence they reach a conclusion that flies in the face of existing facts contrary to what is suggested by kaempfer and lowenberg kl and contrary to the implications of their model the evidence clearly indicates there is an unequivocal bias against the use of import restrictions in favor of export controls the recent history of economic sanctions shows that only somewhat more than one third of sanction episodes involved both export and import controls further gary hufbauer and jeffrey schott 1985 observe that in instances where only one or the other is invoked export controls are almost always preferred to restrictions on imports 2 an almost exclusive reliance on export controls in economic foreign policy measures is particularly evident in the actions of the united states in the 1970s 3 the purpose of this comment is to explore the causes of this asymmetry there are at least three reasons why export controls have been favored over import controls reasons that play no part in the kl model first the general agreement on tariffs and trade gatt has institutionalized a bias against import barriers in favor of export controls second in the united states domestic legal constraints favor export controls and discourage import controls third as will be argued export controls are more easily reversed than import controls and reversibility is a desirable component in any foreign policy based trade intervention consider these points in turn in the 1946 1948 period during which time the gatt was first negotiated trade barriers were identified most often with those artificial impediments to trade that restrict foreign access to domestic markets especially tariffs for this reason gatt rules and actions have sought primarily to dismantle import barriers john jackson 1969 p 502 notes that despite the fact that extensive export controls do exist there has been only one complaint with respect to such controls reflected in gatt documents this is the czechoslovakian complaint against the united states in 1949 for the imposition of discriminatory export controls 4 jackson p 502 observes that there is very little if any effective gatt policing of export control policy and he comments later p 539 that insofar as any gatt obligations can be avoided without consequences this avoidance operates in effect as an exception this suggests that those foreign policy export controls that are pro department of economics university of arizona tucson az 85721 i thank alan deardorff bernard hoekman and robert stem for helpful discussions on work related to this note my thanks also to two anonymous referees for their constructive comments see p 28 and tables 4 1 4 5 pp 70 77 hufbauer and schott 1985 2ibid p 28 3see for example richard cooper 1987 pp 301 302 and p 305 and kenneth abbott 1981 p 741 4this is confirmed more recently by barry carter 1988 p 97 the only other event involving export restrictions challenged before the gatt was the u s embargo against nicaragua in 1985 which involved both import and export restrictions

sanctions in networks abstract in this paper we contribute to the sender target models of sanctions by explicitly incorporating the linkages social political or economic that bind the sender and target to other agents given any network model and architecture we draw attention to two factors that play a key role in determining the efficacy of sanctions in reducing the frequency of violations these are respectively strategic complementaritiesbetween the sanctioning action deleting link with target and number of direct links of the sender and the externalities imposed on the sender by third parties we examine the role played by these factors both in the short run when links can only be deleted and the long run when links can also be added as well as when sanctions are unilateral the sender can only delete own links or multilateral the sender can impose on common allies to sever links to the target our analysis allows an active role to the target to build an opposing coalition to deflect sanctions and to third parties to engage in sanction busting it also extends to multiple senders and targets existence of interest groups within sender and target with dissimilar objectives and signed networks allowing both antagonistic and cordial bilateral relationships

strictly fair allocations in large exchange economies in this paper we introduce the concept of a strictly fair allociation and investigate the set of strictly fair allocations in large exchange economies we prove that when agents utility functions are differentiable the set of strictly fair allocations coincides with the set of equal income walrasian equilibria this is shown using both the limit theorem approach and the limit economy approach we also extend the analysis to economies that have both atoms and an atomless sector these results substantially improve upon the existing characterizations of equal income walrasian equilibria in terms of economic efficiency and economic equity

swords or plowshares a theory of the security of claims to property this paper develops a general equilibrium model of the allocation of resources among appropriative and productive activities the model emphasizes the distinction between offensive weapons which are the instruments of predation and fortifications which provide defense against predation the analysis of this model shows how the equilibrium security of claims to property is determined the analysis focuses on the possibility of a nonaggressive equilibrium in which no resources are allocated to offensive weapons and claims to property are fully secure we also analyze the complex relation between economic welfare and the security of claims to property we find for example that a relatively poor agent could be better off in an equilibrium with less secure claims to property

vickrey clarke groves mechanisms and perfect competition abstract we present a game theoretic mechanism characterization of perfect competition we prove the perfectly competitive mechanism is the only pareto optimal individually rational dominant strategy allocation mechanism thus perfect competition is uniquely capable of efficiently and non coercively solving the incentive bargaining problem when there is incomplete information i e when each individual knows his own tastes and production possibilities better than anyone else we also show one can interpret any dominant strategy demand revealing mechanism as working because it mimics the reward scheme that characterizes the perfectly competitive market namely the marginal product reward scheme

challenges of the maize seed industry in eastern and southern africa a compelling case for private public intervention to promote growth abstract following the liberalization and restructuring of the seed sector the maize seed industry in eastern and southern africa has witnessed a proliferation of private seed companies whereas the total number of registered maize seed companies in major maize producing countries increased four fold between 1997 and 2007 the quantity of seed marketed barely doubled suggesting that the seed production and deployment environment is less than perfect a study involving over 92 of all seed providers in east and southern africa in 2007 showed that a number bottlenecks affect the entire maize seed value chain the lack of access to credit constitutes a significant barrier to entry until governments and development partners make credit available to seed entrepreneurs directly or through risk sharing arrangements with commercial banks national seed companies will not grow leaving the seed sector monopolized by the regional and multinational seed companies in addition the transfer of genetic materials between public and private sectors should be improved to allow easy access by seed companies to suitable and adapted varieties to allow for rapid regional spillovers of varieties released in one country to similar agro ecologies in different countries the implementation of the harmonized regional seed laws and regulations should be expedited finally the best strategies that increase the adoption of improved maize varieties should be explored and implemented to enhance seed demand

fair allocations in large economies the purpose of this paper is the study of problems of equity in an economy with many agents conditions are given under which every equitable and pareto optimal allocation is a competitive equilibrium with equal incomes for all agents the results are also of potential relevance for the literature on incentive compatibility since the allocations that are obained through incentive mechanisms in large economies turn out to be equitable

intertemporal optimality in a closed linear model of production abstract the paper presents the main results on intertemporal optimality with discounting in a closed linear model of production including the price characterization of optimal programs the existence of a steady state optimal program and a turnpike property of optimal programs from arbitrary initial stocks some of these results are used to provide a characterization of the optimality of competitive programs in terms of a decentralizable condition

equilibrium structure in an economic model of conflict four different types of equilibrium are possible within a two player model of society where only armed self enforcement of property rights is possible the main underlying parameters are the total resource endowment and the initial distribution of this endowment between the players the parameter space is partitioned into regions in which the respective types of equilibrium occur the equilibrium types involve positive arms expenditure by respectively neither player the richer player and both players the latter case involves a sub type in which the poorer player s entire endowment is expended on arms jel d30 d72 d74

multi task incentive contract and performance measurement with multidimensional types abstract this paper provides a new explanation for the dominance of the low powered incentive contract over the high powered incentive contract using a hybrid model of moral hazard and adverse selection we first show that unobservable risk aversion or cost leads to low powered incentives we then consider the case where both risk aversion and cost of the agent are unobservable to the principal this multidimensional mechanism design problem is solved under two assumptions with regard to the structures of performance measurement system and wage contract it is shown that if the deterministic and stochastic components of performance measures vary proportionally the principal is inclined to provide a low powered incentive contract moreover it is shown that if the base wage depends on a quadratic function rather than the direction of the performance wage vector no incentive is provided for most of the performance measures in an orthogonal performance measurement system