substitute goods auctions and equilibrium this paper identifies two notions of substitutes for auction and equilibrium analysis weak substitutes the usual price theory notion guarantees monotonicity of t tonnement processes and convergence of clock auctions to a pseudo equilibrium but only strong substitutes which treats each unit traded as a distinct good with its own price guarantees that every pseudo equilibrium is a walrasian equilibrium that the vickrey outcome is in the core and that the law of aggregate demand is satisfied when goods are divisible weak substitutes along with concavity guarantees all of the above properties except for the law of aggregate demand

walrasian equilibrium with gross substitutes in this paper we study the problem of efficient production and allocation of indivisible objects among a set of consumers we assume that the agents preferences depend on the bundle of objects and the quantity of money they consume furthermore we assume that preferences are quasilinear in money and that agents have a large endowment of money with indivisibilities it is well known that many familiar properties of the utility functions fail to ensure existence in their striking analysis of the matching problem kelso and crawford 5 introduce the gross substitutes gs condition which ensures the non emptiness of the core we propose two new conditions and show that with quasilinearity they are equivalent article id jeth 1999 2531 available online at http www idealibrary com on

back to fundamentals equilibrium in abstract economies we propose a new abstract definition of equilibrium in the spirit of competitive equilibrium a profile of alternatives and a public ordering expressing prestige price or a social norm such that each agent prefers his assigned alternative to all lower ranked ones the equilibrium operates in an abstract setting built upon a concept of convexity borrowed from convex geometry we apply the concept to a variety of convex economies and relate it to pareto optimality the magic of linear equilibrium prices is put into perspective by establishing an analogy between linear functions in the standard convexity and primitive orderings in the abstract convexity jel c90 d11 in this paper we return to the fundamental concept of competitive equilibrium and extend the notion to a more abstract setting the extension is based on the idea that competitive equilibrium is a method of creating harmony in an interactive situation with a feasibility restriction and self interested agents it is built around a public ordering of the alternatives which either limits the choices available to the agents or systematically influences their preferences in the standard economic setting this ordering is given by prices that apply equally to all agents these prices determine consumers choice sets and producers preferences we propose an analogous solution concept adjusted to fit more abstract situations in which valuation using prices is replaced by valuation according to a public ordering the road to the construction of the equilibrium concept starts with a discussion of the notion of convexity in the euclidean setting the algebraic notion of convexity is central to the standard analysis of competitive equilibrium since we primarily consider settings that lack an algebraic structure we employ a more abstract form of convexity definitions of convexity involve the primitive phrase b is between the elements a 1 a l in an euclidean space this means that b is an algebraic con vex combination of a 1 a l however the phrase also has a common use in daily conversation for example one can say that game theory is between mathematics and economics and that canada is culturally between the united states the united kingdom and france to accommodate this the first step will be to borrow a formal

political bias and war we examine the incentives for countries to go to war as they depend on the comparison between how much their pivotal decision makers have at risk and how much they stand to gain from a war how this ratio compares to the country at large is what we term political bias if there is no political bias then there are always payments that one country would like to make to the other that will avoid a war in the presence of commitment or enforceability of peace treaties if there is a bias on the part of one or both countries then war can result and in some cases cannot be prevented by any transfer payments we examine how war technology and relative wealth levels interact with political bias in determining whether countries make transfers go to war and form alliances our results shed some new light on the uneven contender paradox and the interpretation of the democratic peace

electricity planning and implementation in sub saharan africa a systematic review abstract universal electricity access is an important development objective and the focus of a number of key global un initiatives while robust electricity planning is widely believed to be a prerequisite for effective electrification to date no comprehensive overview of electricity planning research has been undertaken on sub saharan africa the world region with the lowest access rates this paper reviews quantitative and qualitative electricity planning and related implementation research considering each of the 49 sub saharan african countries the four regional power pools and the sub continent as a whole applying a broad understanding of electricity planning and a practical limit of 20 reviewed articles per country and region 306 relevant peer reviewed journal articles are included in this review a general classification scheme is introduced that classifies the planning literature along the addressed value chain depth number of different analysed criteria and number of evaluated decision alternatives the literature is found to be strongly clustered in a few countries with less than 5 identified relevant articles in 36 of the 49 countries the total amount of articles per year is clearly increasing over time addressing technology choice operation distribution and implementation analyses although including different high level criteria in analysing electricity systems is common the literature is only starting to use formalised multi criteria decision making mcdm tools the review indicates that 63 of relevant articles favour renewable energy technologies for their given problems frequently mentioned success factors for electrification in sub saharan africa include adequate policy design sufficient finance and favourable political conditions while considerable regional and methodological literature gaps are apparent the literature in this review identifies a rich and fruitful ground for future research to fill these gaps

housing markets with indivisibilities abstract a model of a rental housing market in which houses are treated as indivisible commodities is presented a recursive equation that determines a competitive equilibrium is provided and it is argued that this competitive equilibrium is representative of the set of all competitive equilibria using this representative equilibrium several propositions on comparative statics are considered that have to do with how the competitive rents change when certain parameters of the model change

does commercialization undermine the benefits of decentralization for local services provision evidence from mexico s urban water and sanitation sector summary decentralization has been promoted as a means to better reflect citizen preferences and improve local services many developing countries decentralized and promoted neoliberal policies such as commercialization simultaneously leaving mayors with the responsibility of improving public services through self financing reforms this study evaluates experiences in three mexican cities to assess whether decentralization and commercialization practices have resulted in improved water and sanitation services it finds that commercialization has increased social conflict surrounding urban services provision and that local institutional constraints further undermine mayor s ability to adopt politically contentious policies the result has been stalled and uneven service improvements

substitutes and stability for matching with contracts we consider the matching problem with contracts of hatfield and milgrom 2005 and we introduce new concepts of bilateral and unilateral substitutes we show that bilateral substitutes is a sucient condition for the existence of a stable allocation in this framework however the set of stable allocations does not form a lattice under this condition and there does not necessarily exist a doctor optimal stable allocation under a slightly stronger condition unilateral substitutes the set of stable allocations still does not necessarily form a lattice with respect to doctors preferences but there does exist a doctor optimal stable allocation and other key results such as incentive compatibility and the rural hospitals theorem are recovered

powering africa s sustainable development the potential role of nuclear energy abstract the electricity deficit is one of the most serious contemporary issues facing sub saharan africa many countries in the region have insufficient generation capacity to meet rapidly rising demand electricity shortages have become a binding and powerful constraint on the continent s sustainable development their resolution will require coordinated effort to improve the effectiveness and governance of the region s utilities and to significantly scale up generation capacity a broad portfolio of low carbon low c technologies needs to be deployed in order to address the electricity deficit in a cost effective way and not be disruptive to economic growth since nuclear power can deliver low c electricity in bulk reliably and without intermittency it could make a significant contribution towards resolving africa s power crisis however the post fukushima safety concerns related to large nuclear plants with substantial radioactive inventories will be especially pronounced in africa moreover large scale reactors with huge upfront investment requirements are likely to be unsuitable for capital constrained african countries with small electricity grids one promising direction for nuclear development in africa might be to downsize reactors from the gigawatt scale to less complex smaller units with substantially smaller radioactive inventory that are more affordable

competitive equilibrium with indivisibilities abstract this paper studies an exchange economy with a finite number of agents in which each agents is initially endowed with a finite number of personalized indivisible commodities we observe that the equivalence theorem of the core and the competitive equilibrium may not hold for this economy when the coalitional form game is generated in the standard manner we provide an alternative definition of the coalitional form game to resolve this problem so that the balancedness of the new defined game provides a useful necessary and sufficient condition for the existence of competitive equilibrium for the original economy journal of economic literature classification numbers c71 d41 d51

the lifeboat problem abstract we study an all pay contest with multiple identical prizes lifeboat seats prizes are partitioned into subsets of prizes lifeboats players play a two stage game first each player chooses an element of the partition a lifeboat then each player competes for a prize in the subset chosen a seat we characterize and compare the subgame perfect equilibria in which all players employ pure strategies or all players play identical mixed strategies in the first stage the partitioning of prizes can lead to coordination failure when players employ nondegenerate mixed strategies in these equilibria some rents are sheltered and rent dissipation is reduced

a double track adjustment process for discrete markets with substitutes and complements we propose a new walrasian tatonnement process called a double track procedure for efficiently allocating multiple heterogeneous indivisible items in two distinct sets to many buyers who view items in the same set as substitutes but items across the two sets as complements in each round of the process a walrasian auctioneer first announces the current prices for all items buyers respond by reporting their demands at these prices and then the auctioneer adjusts simultaneously the prices of items in one set upward but those of items in the other set downward it is shown that this procedure converges globally to a walrasian equilibrium in finitely many rounds

introduction a symposium on the predatory state economists have adopted two broad perspectives on the state contractual i e provider of public goods and services and predatory coercive and extractive by a predatory state we mean a state that promotes the private interests of dominant groups within the state such as politicians the army and bureaucrats or influential private groups with strong lobbying powers neo institutional economists support an extended version of the contractual perspective in which the state is not simply a benevolent dictator but may itself be composed of predators however it considers predation as only a means to promote protection by contrast a predatory vision of the state argues that while protection and predation are two faces of the same coin a predatory state protects only to promote its predation on the private sector this symposium explores how a predatory approach to the state can shed light on all types of state from liberal democratic to authoritarian and failed ones both in the past and present

stability in a network economy the role of institutions abstract we consider an economy in which agents are embedded in a network of potential value generating relationships agents are assumed to be able to participate in three types of economic interactions autarkic self provision bilateral interaction and multilateral collaboration through endogenously provided platforms we introduce two stability concepts and provide sufficient and necessary conditions on the network structure that guarantee existence in cases of the absence of externalities link based externalities and crowding externalities we show that institutional arrangements based on socioeconomic roles and leadership guarantee stability in particular the stability of more complex economic outcomes requires more strict and complex institutional rules to govern economic interactions we investigate strict social hierarchies tiered leadership structures and global market places

the paradox of state retrenchment in sub saharan africa the micro level experience of public social service provision summary over the past 30 years in africa neoliberal economic reform has meant a major retrenchment of the state provision of health and education with paradoxical local effects based on an analysis of 2005 afrobarometer data the study finds that the rural poor are more likely to use public schools and clinics than the urban better off the data suggest that a two tiered social service system now exists across many african countries where the rural poor may have little choice but to use public social services while the urban better off choose to pay for private alternatives the author argues that concerns about ensuring absolute levels of access have obscured attention to the micro experience and quality of social service delivery

stability and competitive equilibrium in trading networks we introduce a model in which agents in a network can trade via bilateral contracts we find that when continuous transfers are allowed and utilities are quasi linear the full substitutability of preferences is sufficient to guarantee the existence of stable outcomes for any underlying network structure furthermore the set of stable outcomes is essentially equivalent to the set of competitive equilibria and all stable outcomes are in the core and are efficient by contrast for any domain of preferences strictly larger than that of full substitutability the existence of stable outcomes and competitive equilibria cannot be guaranteed

economics and the biologists a review of geerat j vermeij s nature an economic history this essay reviews and criticizes vermeij s nature an economic history and places it in the context of evolutionary economics vermeij presents a natural history written in what he considers economic terms and argues that biologists should know more about economics while the exchanges between economics and biology can sometimes be hazardous and misleading quite a bit could be learned by economists from reading this book

wealthier is healthier we estimate the effect of income on health using cross country timeseries data on health infant and child mortality and life expectancy and income per capita we use instrumental variables estimates using exogenous determinants of income growth to identify the pure income effect on health isolated from reverse causation or incidental association the long run income elasticity of infant and child mortality in developing countries lies between 0 2 and 0 4 using these estimates we calculate that over a half a million child deaths in the developing world in 1990 alone can be attributed to the poor economic performance in the 1980s

reactor ageing and phase out policies global and regional prospects for nuclear power generation abstract nuclear is considered as a valuable option for the decarbonization of power generation as it is a no carbon yet commercially consolidated technology however its real prospects are uncertain especially in the oecd countries the main aim of this work is to explore the techno economic implications of policy relevant scenarios for nuclear power designed on the actual prospects in the world regions and developed with the integrated assessment model witch the analysis shows that nuclear generation constantly grows over the century even if in general the nuclear share in the global electricity mix does not significantly change over time if constraints are applied to nuclear deployment the contribution of this technology is compensated by renewables mainly wind and solar pv and to a lower extent by ccs the policy costs related to nuclear phase out are moderate as they are almost completely compensated by innovation and technology benefits in renewables and energy efficiency phase out policies applied only to the oecd regions do not entail any additional policy costs in these regions while non oecd regions marginally benefit from lower uranium prices

slavery and other property rights the institution of slavery is found mostly at intermediate stages of agricultural development and less often among hunter gatherers and advanced agrarian societies we explain this pattern in a growth model with land and labor as inputs in production and an endogenously determined property rights institution the economy endogenously transits from an egalitarian state with equal property rights to a despotic slave society where the elite own both people and land thereafter it endogenously transits into a free labor society where the elite own the land but people are free

the permissible and the forbidden abstract in many economic situations neither prices nor authority rules rather individual behavior is governed by social norms that specify what is allowed socially acceptable and what is forbidden socially unacceptable these norms can emerge in a decentralized way and can serve as a method to bring order to economic situations the key component of our solution concept is a uniform permissible set which plays a role parallel to that of a price system in competitive equilibrium the concept is analyzed and applied to a variety of economic and social settings

contracts versus salaries in matching workers and firms may bargain over general multidimensional contracts they may negotiate over health benefits housing retirement plans etc substitutes on the other hand is the assumption commonly placed on firms preferences to guarantee the existence of stable matchings of workers and firms in this paper i show that when firms regard contracts as substitutes bargaining over contracts can be embedded into a model of bargaining over wages the economics of the embedding is straightforward except for a small twist when a firm and a worker negotiate over a contract they may bargain over many dimensions however the pareto frontier of contracts is in a sense one dimensional what is better for the worker is worse for the firm so pareto optimal contracts may be viewed as salaries with the better contracts for the firm meaning lower salaries and the better contracts for the worker meaning higher salaries the twist is that a firm s ranking over contracts might be affected by the firm s other hires for example health plan a may be better than b for a firm if it has many employees but b beats a if it has few when contracts are substitutes it turns out that the ranking is not affected in this way hatfield and milgrom 2005 present a model of two sided worker firm matching with contracts a firm will hire a collection of workers and will negotiate a contract with each one of them the model is a generalization of kelso and crawford 1982 where each firm and each worker negotiate a wage 1 kelso and crawford show that when firms demands satisfy gross substitutes the core of the matching market is nonempty hatfield and milgrom show that when the firms preferences over contracts satisfy their notion of substitutes the core of the market is nonempty i show that hatfield and milgrom s model can be embedded into the model of kelso and crawford hatfield and milgrom s assumption of substitutability enables an embedding where firms demands for workers satisfy kelso and crawford s notion of gross substitutes as a result the nonemptiness of the core follows from the argument in kelso and crawford and their salary adjustment algorithm finds a stable matching of workers to firms and a vector of supporting salaries hatfield and milgrom s paper is an elegant analysis of two sided matching it simplifies matching models and makes their relationship to auction models more transpar ent their paper contributes much more than showing the nonemptiness of the core when firms and workers can sign general contracts and my result does not diminish

paradoxes of decentralization water reform and social implications in mexico summary decentralized governance of water resources is a centerpiece of mexico s neoliberal reform strategy we analyze decentralization based on urban rural case studies in distinct geographical regions to ascertain whether it is linked to more efficient water management or sustainable use of water resources and to examine its development implications we assess whether or not private sector management is related to a more efficient sustainable and accountable management of water variety of municipal and private management arrangement in four urban areas we find that it has not resulted in efficiency or sustainability gains for agricultural water management irrigation districts in two case studies benefited from the more democratic participatory management by water users under mexico s transference strategy but did not result in greater equity efficiency or sustainability of water use we argue that decentralization in the mexican water sector is context specific and marked by limited benefits privatization is less an instrument aimed at improving efficiency than a channel for preferred treatment for capital accumulation by private entities as well as a legitimized way for the state to transfer the burden of water management to non state institutions the creation of new forms of water institutions requires not the retrenchment of the state but rather its involvement to ensure accountability transparency equity and sustainability

the failures of privatization a comparative investigation of tuberculosis rates and the structure of healthcare in less developed nations 1995 2010 tuberculosis remains a persistent global health problem and key threat to development in poor countries while many nations pursue privatization of healthcare some accounts suggest that private health services are inadequate in addressing the tb burden we utilize panel regression to empirically investigate data from 99 less developed nations from 1995 to 2010 the results illustrate private health expenditures do not significantly impact tb rates while public health expenditures reduce tb rates in developing nations over time thus we caution against international development strategies which promote cuts in public spending and encourage privatization of healthcare as a means to stimulate growth or efficiency

strong tiebout equilibrium under restricted preferences domain abstract we investigate the existence and give a partial characterization of a strong tiebout equilibrium which consists of an endogenously formed partition of the individuals into disjoint jurisdictions with each jurisdiction producing and financing its own public goods and moreover there exists no group of individuals who can all benefit by establishing their own community in particular no single individual finds it desirable to migrate from his equilibrium jurisdiction the existence proof makes use of the notion of consecutive games which we introduce and show that for such games there always exists a partition with a nonempty core

matching with contracts we develop a model of matching with contracts which incorporates as special cases the college admissions problem the kelso crawford labor market matching model and ascending package auctions we introduce a new law of aggregate demand for the case of discrete heterogeneous workers and show that when workers are substitutes this law is satisfied by profit maximizing firms when workers are substitutes and the law is satisfied truthful reporting is a dominant strategy for workers in a worker offering auction matching algorithm we also parameterize a large class of preferences satisfying the two conditions

balance of power and the propensity of conflict we study the role of an imbalance in fighting strengths when players bargain in the shadow of conflict our experimental results suggest in a simple bargaining game with an exogenous mediation proposal the likelihood of conflict is independent of the balance of power if bargaining involves endogenous demand choices however the likelihood of conflict is higher if power is more imbalanced even though endogenous bargaining outcomes reflect the players unequal fighting strengths strategic uncertainty causes outcomes to be most efficient when power is balanced in turn the importance of exogenous mediation proposals depends on the balance of power

competitive equilibrium in an exchange economy with indivisibilities abstract we analyze an exchange economy in which i all commodities except money are indivisible ii agents preferences can be described by a reservation value for each bundle of indivisible objects and iii all agents are price takers we obtain a necessary and sufficient condition under which market clearing prices exist implications for market mechanisms are discussed journal of economic literatureclassification numbers d51 c78

understanding preferences demand types and the existence of equilibrium with indivisibilities we propose new techniques for understanding agents valuations our classification into demand types incorporates existing definitions substitutes complements strong substitutes etc and permits new ones our unimodularity theorem generalises previous results about when competitive equilibrium exists for any set of agents whose valuations are all of a demand type for indivisible goods contrary to popular belief equilibrium is guaranteed for more classes of purely complements than of purely substitutes preferences our intersection count theorem checks equilibrium existence for combinations of agents with specific valuations by counting the intersection points of geometric objects applications include matching and coalition formation and the product mix auction introduced by the bank of england in response to the financial crisis

health insurance and other risk coping strategies in uganda the case of microcare insurance ltd summary to reduce the burden of health expenditures in developing countries health insurance schemes have become popular and now feature prominently in poverty reduction strategies there is however limited empirical evidence on the effect of such schemes on the livelihoods of clients especially regarding household strategies to finance medical expenditures this paper explores the relationship between health insurance and other risk coping strategies used to finance medical expenditures in uganda insurance is associated with a lower frequency of asset sales but not with lower incidences of borrowing the amount of money borrowed or generated through the sales of assets is lower for insured households

the dynastic cycle and the stationary state a dynastic cycle is a periodic alternation of society between despotism and anarchy in a society of farmers rulers and bandits population growth simultaneously impoverishes farmers and reduces the ruler s surplus per head society evolves into a despotic stationary state or into a dynastic cycle dependent on whether poverty among farmers chokes off population growth before the surplus shrinks to the point where rulers turn to banditry copyright 1989 by american economic association

equilibrium in the jungle in the jungle power and coercion govern the exchange of resources we study a simple stylized model of the jungle that mirrors an exchange economy we de ne the notion of jungle equilibrium and demonstrate that a number of standard results of competitive markets hold in the jungle jel classi cation c7 d4 s477 b201

equilibria and indivisibilities gross substitutes and complements this paper examines an exchange economy with heterogeneous indivisible objects that can be substitutable or complementary we show that a competitive equilibrium exists in such economies provided that all the objects can be partitioned into two groups and from the viewpoint of each agent objects in the same group are substitutes and objects across the two groups are complements this condition generalizes the well known kelso crawford gross substitutes condition and is called gross substitutes and complements we also provide practical and typical examples from which substitutes and complements are both jointly observed