the problem of multiple commons a market design approach abstract there are several locations each of which is endowed with a resource that is specific to that location each agent will go to a single location and harvest some of the resource there several agents may go to each location and thereby cause a congestion effect that is modeled in a general way we assign harvesting rights based on preferences alone though we later extend the model to accommodate private endowments of money we find the best allocation rule in the class of rules that are strategy proof anonymous and that satisfy a weak continuity property for a special class of preferences we also find an ascending mechanism similar to an auction that implements the rule the rule coincides with a special pseudo market equilibrium wherein agents buy their desired resource with tokens distributed by the social planner

the political economy of urban food security in sub saharan africa abstract sub saharan african cities in the late 1990s face a daunting set of problems including rapid growth increasing poverty deteriorating infrastructure and inadequate capacity for service provision even as a renewed debate is shaping up around issues of urban development there is little attention given to the question of urban food security whereas in the 1970s and 1980s urban food problems in africa commanded political attention the nature of urban food insecurity in the 1990s is such that it has tended to lose political importance this is largely because in the 1970s the problem was one of outright food shortages and rapid price changes that affected large portions of the urban population simultaneously the impact of structural adjustment continued rapid growth and an increase in poverty make urban food insecurity in the 1990s primarily a problem of access by the urban poor under circumstances where the urban poor spend a very large portion of their total income on food urban poverty rapidly translates into food insecurity the lack of formal safety nets and the shifting of responsibility for coping with food insecurity away from the state towards the individual and household level has tended to atomize and muffle any political response to this new urban food insecurity this paper briefly reviews urban food insecurity and generates a set of empirical questions for an analysis of food and livelihood security in contemporary urban sub saharan africa and then examines historical and contemporary evidence from kampala uganda and accra ghana to suggest some tentative conclusions

position auctions with consumer search this paper examines a model in which advertisers bid for sponsored link positions on a search engine the value advertisers derive from each position is endogenized as coming from sales to a population of consumers who make rational inferences about rm qualities and search optimally consumer search strategies equilibrium bidding and the welfare benets of position auctions are analyzed implications for reserve prices and a number of other auction design questions are discussed

returns to micro entrepreneurship in an emerging economy a quantile study of entrepreneurial indonesian households welfare presenting low individual returns but providing households with livelihoods and means to cope with economic vulnerability micro entrepreneurship s evaluation should include both context and heterogeneity using a four wave panel of 9 157 indonesian households this study proposes a quantile estimation of micro entrepreneurship s effects on four household level complementary measures of welfare income consumption household and total assets it evidences substantial positive but decreasing effects on the four measures with the highest relative returns for the poorest for this category micro entrepreneurship primarily provides returns in the form of income translating into higher relative consumption but more importantly into a greater relative assets accumulation

truthfulness with value maximizing bidders on the limits of approximation in combinatorial markets abstract in some markets bidders want to maximize value subject to a budget constraint rather than payoff this is different to the quasilinear utility functions typically assumed in auction theory and leads to different strategies and outcomes we refer to bidders who maximize value as value bidders while simple single object auction formats are truthful standard multi object auction formats allow for manipulation it is straightforward to show that there cannot be a truthful and revenue maximizing deterministic auction mechanism with value bidders and general valuations approximation has been used as remedy to achieve truthfulness on other mechanism design problems and we study which approximation ratios we can get from truthful mechanisms we show that the approximation ratio that can be achieved with a deterministic and truthful approximation mechanism with n bidders cannot be higher than 1 n for general valuations for randomized approximation mechanisms there is a framework with a ratio that is tight

heterogeneity in informal salaried employment evidence from the egyptian labor market survey summary this paper contributes to the continuing debates on the mechanisms driving labor market informality in developing countries by proposing an innovative way to discriminate between segmented and competitive markets an empirical analysis is applied to egyptian paid employment in the highly dynamic context of 1998 2006 the study is based on recent nonparametric methods applied to estimate the model with essential heterogeneity the model is extended to decomposing the treatment effects into unobserved and observed components the results show triple heterogeneity of workers on the egyptian labor market offering support to both segmented and competitive views on informal labor

simple strategy proof approximately walrasian mechanisms abstract this note provides an indirect analysis of the incentive properties of the walrasian mechanism it presents mechanisms under which truth telling is a dominant strategy in finite exchange economies in contrast to the walrasian mechanism and whose outcomes generically approximate walrasian ones for large economies these mechanisms provide new insights on the well know trade off between efficiency and incentive compatibility in finite economies journal of economic literature classification numbers d50 d71 d78

a multi item auction with budget constrained bidders and price controls we extend the multi item auction model of talman and yang 2008 and andersson et al 2015 by considering both unit demand bidders with budget constraints and price controls on bidding items due to these budget and price restrictions a walrasian equilibrium generally fails to exist to achieve efficiency we propose a rationed equilibrium whose allocation is in the core we also construct an ascending auction to find the proposed rationed equilibrium in pseudo polynomial time

constrainedly fair job assignments under minimum wages a number of jobs are to be assigned to a greater number of workers while having to abide by the law of minimum wages firms must determine who should be assigned which job and at what salary in such situations fair envy free allocations usually fail to exist to cope with this situation this paper proposes a new concept of fairness called constrained fairness among the set of constrainedly fair allocations the so called constrainedly fair and minimal allocations are of particular interest the reason for this is that the salaries are not only compatible with the minimum wages they are also optimal from the standpoint of cost minimizing firms and the assignment of jobs is efficient from the viewpoint of workers a convergent dynamic procedure that identifies constrainedly fair and minimal allocations is proposed furthermore strategic properties of the mechanism are derived and two notions of efficiency are evaluated

a parametrization of the auction design space abstract we present an extensive breakdown of the auction design space that captures the essential similarities and differences of many auction mechanisms in a format more descriptive and useful than simple taxonomies this parametrization serves as an organizational framework in which to classify work within the field and uncovers parameter combinations corresponding to novel mechanisms the structured characterization of auction rules can be exploited for the modular design of configurable auction servers it also facilitates the communication of auction rules to software agents enabling the automation of flexible market based negotiation journal of economic literature classification numbers c70 d44

on minimal ascending auctions with payment discounts the literature on ascending combinatorial auctions yields conflicting insights regarding the possibility to implement the vickrey payoffs for general valuations we introduce the class of minimal ascending auctions a class which allows one to disconnect the final payments from the final bids but which prohibits the raising of the price vector of a provisionally winning bidder we first establish the impossibility of implementing the vickrey payoffs for general valuations second we propose a minimal ascending auction that yields a bidder optimal competitive equilibrium thanks to payment discounts

using first price auctions to sell heterogeneous licenses abstract this paper considers three alternative ways to sell heterogeneous licenses via a first price format when there is single unit demand it has been suggested that incorporating a first price element may bolster competition in this case klemperer paul d 2002 what really matters in auction design journal of economic perspectives 16 169 189 in a controlled laboratory setting we compare the performance of the simultaneous first price auction the sequential first price auction and the simultaneous descending auction with that of the simultaneous ascending auction the experiments involve several bidding environments of varying complexity we find that the simultaneous ascending auction achieves the highest levels of efficiency but also has drawbacks i its revenues are low and variable ii per license profits vary and iii the incidence of winner s curse outcomes is high seller s revenues are highest when the licenses are sold in a sequential first price auction in decreasing order of quality

internet advertising and the generalized second price auction selling billions of dollars worth of keywords we investigate the generalized second price gsp auction a new mechanism used by search engines to sell online advertising although gsp looks similar to the vickrey clarke groves vcg mechanism its properties are very different unlike the vcg mechanism gsp generally does not have an equilibrium in dominant strategies and truth telling is not an equilibrium of gsp to analyze the properties of gsp we describe the generalized english auction that corresponds to gsp and show that it has a unique equilibrium this is an ex post equilibrium with the same payoffs to all players as the dominant strategy equilibrium of vcg

the strategy structure of some coalition formation games in coalitional games with side payments the core predicts which coalitions form and how benefits are shared the predictions however run into difficulties if the core is empty or if some coalitions benefit from not blocking truthfully these difficulties are analyzed in games in which an a priori given collection of coalitions can form as the collection of pairs of buyer seller in an assignment game the incentive properties of the core and of its selections are investigated in function of the collection furthermore the relationships with vickrey clarke groves mechanisms are drawn

robust auctions for revenue via enhanced competition in robust auctions for revenue via enhanced competition t roughgarden i talgam cohen and q yan revisit the classic bulow klemperer result this result compares the revenues of two well know

online ad auctions i describe how search engines sell ad space using an auction i analyze advertiser behavior in this context using elementary price theory and derive a simple way to estimate the producer surplus generated by online search advertising it appears that the estimated value of online advertising tends to be between 2 and 2 3 times advertising expenditures jel d44 auctions d21 firm behavior

decentralized matching markets with endogenous salaries abstract in a shapley shubik assignment problem with a supermodular output matrix we consider games in which each firm makes a take it or leave it salary offer to one applicant and a match is made only when the offer is accepted by her we consider both one shot and multistage games in either game we show that there can be many equilibrium salary vectors which are higher or lower than the minimum competitive salary vector if we exclude artificial equilibria applicants equilibrium salary vectors are bounded above by the minimal competitive salary vector while firms equilibrium payoff vectors are bounded below by the payoff vector under the minimum competitive salary vector this suggests that adopting the minimum competitive salary vector as the equilibrium outcome in decentralized markets does not have a strong justification

double implementation in a market for indivisible goods with a price constraint i consider the problem of assigning indivisible objects to agents in which each agent pays a price for his object and all prices sum to a given constant the objective is to select an assignment price pair that is envy free with respect to the agents true preferences i propose a simple mechanism whereby agents announce valuations for all objects and an envy free allocation is selected with respect to these announced preferences i prove that the proposed mechanism implements both in nash and strong nash equilibrium the set of true envy free allocations

a theory of jump bidding in ascending auctions abstract jump bidding is a commonly observed phenomenon that involves bidders in ascending auctions submitting bids higher than required by the auctioneer such behavior is typically explained as due to irrationality or to bidders signaling their value we present field data that suggests such explanations are unsatisfactory and construct an alternative model in which jump bidding occurs due to strategic concerns and impatience we go on to examine the impact of jump bidding on the outcome of ascending auctions in an attempt to resolve some policy disputes in the design of ascending auctions

food security gender and occupational choice among urban low income households this paper examines an adaptive strategy using occupational choice that can be undertaken by household members in urban poor areas to help ensure their access to food our investigation focuses on self employed women and men in 14 predominantly slum communities in bolivia ecuador philippines and thailand results of our empirical analysis show that choice of business is associated with household vulnerability to food insecurity with women in vulnerable households likely to engage in food enterprises the findings suggest that urban low income households can mitigate the risk of food shortage through the selection of an enterprise activity that earns money income and is a direct source of food for consumption

self employment and self selection in developing country labor markets labor markets in less developed countries ldcs have traditionally been characterized as non competitive this view is expressed in well known models in the development economics literature for example the labor surplus model of lewis 16 asserts that labor in rural areas of ldcs in early stages of development is so abundant that if the wage rate were determined competitively it would be below the subsistence level hence institutions are assumed to arise to determine the wage rate non competitively and to provide the resulting excess supply of labor to agriculture with a subsistence level of living the harristodaro 11 model of rural urban migration asserts that labor unions minimum wage laws public sector hiring practices and other institutional factors tend to keep formal sector wages in urban areas above labor market clearing levels the resulting excess supply of labor in urban areas is assumed to survive at a subsistence level by becoming selfemployed in the low productivity informal sector recent empirical studies provide little support for the non competitive view of ldc labor markets evidence from india thailand malaysia kenya and guatemala suggests that labor markets are much less imperfect than often assumed an important empirical finding in several of these studies is that self employed workers appear to have higher earnings than their wage employee counterparts in urban areas 2 this fact is inconsistent with the notion that self employment is typically a low productivity occupation engaged in by individuals who are searching for scarce well paying formal sector jobs the purpose of this study is to analyze and estimate a model of individual choice between wage and self employment in the ldc context the model incorporates a production function in the self employment sector that includes managerial ability as an input analysis of the influence of managerial ability on the choice of self employment leads to a theory that can explain the observed pattern of earnings of the urban self employed compared to wage employees implications of the model for estimation of production function

poverty food security nexus evidence from a survey of urban slum dwellers in kolkata we explore the poverty food security nexus using an experience based indicator of food security constructed using a cross section sample of slum households in kolkata within the framework of a simultaneous ordered probit model we find a poor household is also likely to be food insecure additionally education gender and household composition are major drivers of food insecurity among low income urban households with the policy implication that anti poverty policies should be successful in eliminating household food insecurity however they need to be complemented with human capital investment and gender empowerment to be most effective

vickrey dutch procurement auction for multiple items we consider a setting where there is a manufacturer who wants to procure multiple items from a set of suppliers each of whom can supply one or more of these items bundles we design an ascending price auction for such a setting which implements the vickrey clarke groves outcome and truthful bidding is an ex post nash equilibrium our auction maintains non linear and non anonymous prices throughout the auction this auction has a simple price adjustment step and is easy to implement in practice as offshoots of this auction we also suggest other simple auctions in which truthful bidding is not an equilibrium by suppliers which may be suitable where incentives to suppliers are not a big concern computer simulations of our auction show that it is scalable for the multi unit case and has better information revelation properties than its descending auction counterpart

elicitation of honest preferences for the assignment of individuals to positions the problem of eliciting honest preferences from individuals who must be assigned to a set of positions is considered individuals know that they will be charged for the positions to which they are assigned a set of prices that provide no incentive for the individual to misrepresent his preferences is suggested it is shown that these prices constitute an element of the optimal solution to the dual of a linear programming assignment problem both the optimal allocation and the prices to be charged can be derived by solving two linear programming problems once preferences have been elicited the procedure can usefully be viewed as a simulation of a competitive market under conditions where such a market cannot be expected to function well it results in an efficient allocation where all resources are valued at their opportunity costs and consumer surplus is maximized its outcome thus has the desirable properties of competitive market equilibria

an algorithm for identifying fair and optimal allocations the concept of a fair and optimal allocation was recently introduced by sun and yang sun n yang z 2003 a general strategy proof fair allocation mechanism economics letters 81 73 79 this note states some basic properties of fair and optimal allocations and provides a simple algorithm for identifying them c 2007 elsevier b v all fights reserved

approximation in mechanism design with interdependent values abstract this paper studies the revenue maximization problem in environments wherein buyers have interdependent values and correlated types we show that 1 when the system of feasible sets is a matroid and buyer valuations satisfy a single crossing condition the generalized vickrey clarke groves mechanisms with lazy reserves vcg l are ex post incentive compatible and ex post individually rational 2 if in addition the valuation distribution satisfies a generalized monotone hazard rate condition the vcg l mechanism with conditional monopoly reserves is approximately optimal then we construct an ascending auction that implements the truth telling equilibrium of a vcg l mechanism in ex post equilibrium finally we discuss the connection between the vcg l mechanisms and greedy algorithms studied in lehmann et al 2002 and deferred acceptance auctions studied in milgrom and segal 2014 and the impact of competition by proving a bulow and klemperer 1996 type result

ascending price vickrey auctions abstract we show that an ascending price auction for multiple units of a homogeneous object proposed by ausubel i raises prices for packages until they reach those nonlinear and non anonymous market clearing prices at which bidders get their marginal products and ii the auction is a primal dual algorithm applied to an appropriate linear programming formulation in which the dual solution yields those same market clearing prices we emphasize the similarities with efficient incentive compatible ascending price auctions to implement vickrey payments when there is a single object or when objects are heterogeneous but each buyer does not desire more than one unit a potential benefit of these common threads is that it helps to establish the principles upon which vickrey payments may be implemented through decentralized incentive compatible procedures

measuring food insecurity the frequency and severity of coping strategies abstract defining and interpreting food security and measuring it in reliable valid and cost effective ways have proven to be stubborn problems facing researchers and programs intended to monitor food security risks this paper briefly reviews the conceptual and methodological literature on food insecurity measurment describes a particular method for distinguishing and measuring short term food insecurity at the household level and discusses ways of generalizing the method the method developed enumerates the frequency and severity of strategies relied on by urban households when faced with a short term insufficiency of food this method goes beyond more commonly used measures of caloric consumption to incorporate vulnerability elements of food insecurity as well as the deliberate actions of household decision makers when faced with food insufficiency

transferring ownership of public housing to existing tenants a market design approach this paper explores a housing market with an existing tenant in each house and where the existing tenants initially rent their houses the idea is to identify equilibrium prices for the housing market given the prerequisite that a tenant can buy any house on the housing market including the one that he is currently possessing or continue renting the house he is currently occupying the main contribution is the identification of an individually rational equilibrium selecting and group non manipulable price mechanism in a restricted preference domain that contains almost all preference profiles in this restricted domain the identified mechanism is the minimum price equilibrium selecting mechanism that transfers the maximum number of ownerships to the existing tenants we also relate the theoretical model and the main findings to the u k housing act 1980 whose main objective is to transfer ownerships of houses to existing tenants

an efficient dynamic auction for heterogeneous commodities this paper proposes a new dynamic design for auctioning multiple heterogeneous commodities generalizing earlier work that treated identical objects an auctioneer wishes to allocate one or more units of each of k heterogeneous commodities to n bidders the auctioneer announces a vector of current prices bidders report back quantities demanded at these prices and the auctioneer adjusts the prices units are credited to bidders at the current prices as their opponents demands decline and the process continues until every commodity market clears bidders rather than being required to behave as price takers are permitted to strategically exercise their market power nevertheless with pure private values the proposed auction yields walrasian equilibrium prices an efficient outcome results as from a vickrey clarke groves mechanism but bidders are only required to evaluate their demands along a one dimensional path of prices rather than reporting their utilities over the entire k dimensional consumption set the auction is also more transparent and potentially simpler for bidders to understand and has the advantage of assuring the privacy of the upper portions of bidders demands theoretically the new auction provides a new foundation for convergence to walrasian equilibrium in an exchange economy practically it provides an efficient method for simultaneously auctioning two or more related types of securities for example three month and six month treasury bills it is also potentially useful for auctioning multiple types of communications spectrum for example licenses for paired and unpaired spectrum

joint bidding in the name your own price channel a strategic analysis in this paper we study the name your own price nyop channel we examine theoretically and empirically whether asking consumers to place a joint bid for multiple items rather than bid one item at a time as practiced today can increase nyop retailers profits relatedly we also examine whether allowing consumers to self select whether to place a joint bid or itemwise bids increases retailers profits and consumers surplus we construct a dynamic model that incorporates both demand uncertainty and supply uncertainty to address these issues our theoretical analysis identifies the conditions under which joint bidding can increase both nyop retailers profits and consumers surplus we find that some consumers might bid more for the very same items when they place joint bids the increase in bid amount is related to the fact that joint bidding reduces the chance of mismatch between nyop retailers costs and consumer bids we conducted a laboratory study to assess the descriptive validity of some of the

effect of certified organic production systems on poverty among smallholder farmers empirical evidence from kenya summary this study evaluates the effect of certified organic production on poverty in smallholder production systems data was collected from cross sectional survey of local market oriented peri urban vegetable and rural honey producers in kenya poverty was measured using the multidimensional poverty methodology and endogenous switching probit model used to assess the effect of certified organic production on multidimensional poverty findings were that certified producers were less likely to be multidimensional poor compared to their counterfactual case of not participating in organic certification schemes additionally noncertified producers would be less likely to be poor if they were to participate in organic certification production

a theory of buyer seller networks this paper introduces a new model of exchange networks rather than markets of buyers and sellers it begins with the empirically motivated premise that a buyer and seller must have a relationship a link to exchange goods networks buyers sellers and the pattern of links connecting them are common exchange environments this paper develops a methodology to study network structures and explains why agents may form networks in a model that captures characteristics of a variety of industries the paper shows that buyers and sellers acting strategically in their own self interests can form the network structures that maximize overall welfare

formal measures of the informal sector wage gap in mexico el salvador and peru using comparable micro level data from three countries we ask what type of person works in the informal sector and whether informal workers earn lower wages than observationally equivalent workers in the formal sector the characteristics of informal workers are similar across countries surprisingly when we control for these personal characteristics we find a significant wage premium associated with formal employment in el salvador and peru but a premium associated with work in the informal sector in mexico a model of endogenous selection offers little help in explaining the differences in wage patterns the research casts doubt on the received wisdom that the informal sector always and everywhere is a poorly paid but easily entered refuge for those who have no other employment opportunities this abstract was borrowed from another version of this item

on vickrey type auction procedures abstract although a vickrey type auction provides a dominant strategy for every buyer bidder even in a multi item setting a seller can manipulate the auction this paper attempts to show that the manipulation can be avoided by suitably modifying the initial price vector

the package assignment model we study assignment problems where individuals trade packages consisting of several rather than single objects although buyers reservations values are non additive efficient assignments can be formulated as a linear programming problem in which the pricing functions expressing duality may be non linear in the objects constituting the packages the interconnections among the linear programming formulation walrasian equilibrium and the core are established in the single seller auction version a necessary and sufficient condition is given for the vickrey payoff point to be implementable by a pricing equilibrium journal of economic literature classification numbers c62 d44 d51

on ascending vickrey auctions for heterogeneous objects abstract we construct an ascending auction for heterogeneous objects by applying a primal dual algorithm to a linear program that represents the efficient allocation problem for this setting the auction assigns personalized prices to bundles and asks bidders to report their preferred bundles in each round a bidder s prices are increased when he belongs to a minimally undersupplied set of bidders this concept generalizes the notion of overdemanded sets of objects introduced by demange gale and sotomayor for the one to one assignment problem under a submodularity condition the auction implements the vickrey clarke groves outcome we show that this type of condition is somewhat necessary to do so when classifying the ascending auction literature in terms of their underlying algorithms our auction fills a gap in that literature we relate our results to various ascending auctions in the literature

sequential rules for house allocation with price restrictions this paper considers a housing market with price restrictions on such markets the existence of a unique minimum rationing equilibrium price vector has been established for each preference profile on a general preference domain that contains almost all preference profiles this vector can be used as a key ingredient in a direct and strategy proof allocation mechanism the main contribution of this paper is to provide two price sequences one with increasing prices and one with decreasing prices that both terminate to a minimal rationing equilibrium price vector in a finite number of steps these sequences are demonstrated to play key roles in an english auction and a dutch auction respectively for the considered housing market with price restrictions less

infrastructure provision gender and poverty in indian slums we examine the relationship between infrastructure provision and poverty alleviation by analyzing 500 interviews conducted in serviced and non serviced slums in india using a mixed method approach of qualitative analysis and regression modeling we find that infrastructure was associated with a 66 increase in education among females service provision increased literacy by 62 enhanced income by 36 and reduced health costs by 26 evidence suggests that a gender sensitive consideration of infrastructure is necessary and that a one size fits all approach will not suffice we provide evidence that infrastructure investment is critical for well being of slum dwellers and women in particular

is there a link between quality of employment and indebtedness the case of urban low income households in ecuador the paper explores the incidence of high indebtedness or financial stress among urban poor households in ecuador and demonstrates its relation with the quality of employment we argue that informalisation of employment and in particular job precariousness have consequences on other dimensions of vulnerability such as high debt servicing and financial stress the empirical analysis is based on a 2002 sample survey data of men and women workers in urban poor communities of ecuador by employing an index of job quality we investigate and compare the job quality of women and men workers in these households and find gender based patterns with women working in relatively low quality jobs compared to men moreover there seems to be differentiated levels of debt servicing among women and men that suggests uneven debt burden sharing among household members by means of regression analyses the paper demonstrates that low quality jobs tend to lead to higher debt servicing the results provide a nuanced and illuminating picture of the interconnectedness of employment financial stress and vulnerability

auction protocols for decentralized scheduling decentralized scheduling is the problem of allocating resources to alternative possible uses over time where competing uses are represented by autonomous agents market mechanisms use prices derived through distributing bidding protocols to determine schedules we investigate the existence of equilibrium prices for some general classes of scheduling problems the quality of equilibrium solutions and the behavior of an ascending auction mechanism and bidding protocol to remedy the potential nonexistence of price equilibria due to complementarities in preference we introduce additional markets in combinations of basic goods finally we consider direct revelation mechanisms and compare to the market based approach journal of economic literature classification numbers c62 c70 d44

a simple selling and buying procedure abstract for the assignment game we analyze the following mechanism sellers simultaneously fix their prices first then buyers sequentially decide which object to buy also each buyer may report his or her indifferences along with the previous buyers indifferences to the following buyer the first phase determines the potential prices while the second phase determines the actual matching reporting truthfully the indifferences is always a dominant strategy for the buyers moreover when buyers state their true indifferences the subgame perfect equilibria outcomes of the mechanism correspond to the maximum equilibrium price vector together with optimal matchings journal of economic literature classification numbers c78 d78

ascending price vickrey auctions for general valuations ascending price auctions typically involve a single price path with buyers paying their final bid price using this traditional definition no ascending price auction can achieve the vickrey clarke groves vcg outcome for general private valuations in the combinatorial auction setting we relax this definition by allowing discounts to buyers from the final price of the auction or alternatively calculating the discounts dynamically during the auction while still maintaining a single price path using a notion called universal competitive equilibrium prices shown to be necessary and sufficient to achieve the vcg outcome using ascending price auctions we define a broad class of ascending price combinatorial auctions in which truthful bidding by buyers is an ex post nash equilibrium any auction in this class achieves the vcg outcome and ex post efficiency for general valuations we define two specific auctions in this class by generalizing two known auctions in the literature 11 24

an efficient ascending bid auction for multiple objects when bidders exhibit multi unit demands standard auction methods generally yield inefficient outcomes this article proposes a new ascending bid auction for homogeneous goods such as treasury bills or telecommunications spectrum the auctioneer announces a price and bidders respond with quantities items are awarded at the current price whenever they are clinched and the price is incremented until the market clears with private values this dynamic auction yields the same outcome as the sealed bid vickrey auction but has advantages of simplicity and privacy preservation with interdependent values this auction may retain efficiency whereas the vickrey auction suffers from a generalized winner s curse

random decentralized market processes for stable job matchings with competitive salaries abstract we analyze a decentralized process in a basic labor market where finitely many heterogeneous firms and workers meet directly and randomly in pursuit of higher payoffs over time and agents may behave myopically we find a general random decentralized market process that almost surely converges in finite time to a competitive equilibrium of the market a key proposition en route to this result exhibits a finite sequence of successive bilateral trades from an arbitrary initial market state to a stable matching between firms and workers with a scheme of competitive salary offers

improving identification of demand side obstacles to schooling findings from revealed and stated preference models in two ssa countries summary efforts to expand primary education have shifted from a policy focus on supply building schools to demand side policies human capital theory posits that common demand side obstacles are high direct costs opportunity costs and low perceived benefits constructs that are difficult to measure empirically this study compares strategies to estimate obstacles to schooling through revealed and stated preferences using similar household survey data from two sub saharan african countries the typical determinants of schooling model underestimates demand side obstacles and gender differences and additional useful information for theory testing and policy is derived from analyzing parents stated preferences as well

is consumption too smooth for thirty years it has been accepted that consumption is smooth because permanent income is smoother than measured income this paper considers the evidence for the contrary position that permanent income is in fact less smooth than measured income so that the smoothness of consumption cannot be straightforwardly explained by permanent income theory the paper argues that in postwar u s quarterly data consumption is smooth because it responds with a lag to changes in income

segmented labor markets in ldcs this discussion is confined to the urban labor markets in developing countries and to manual workers it outlines the process by which the urban market for workers of low skill tends to develop a sector of high wage often accompanied by job security and fringe benefits unavailable to the large number of workers outside this sector it views the problem of large wage differentials within the urban manual work force more as one of distribution of income than as creating distortions of income or inefficiency in the neoclassical sense the paper concludes that the difference in efficiency wages and hence of labor costs between different size classes of enteprises could be much less than the observed wage gap the urban economy appears to be characterized by widening wage differentials between the formal and the residual sectors with a declining proportion of the urban labor force employed in the former what happens to income distribution in its lower reaches depends crucially on the dynamism of the self employed sector of petty producers and traders which often shows high returns to small doses of capital and entrepreneurship and which may provide an alternative to job seekers not able to get into the high wage sector

bargaining in stationary networks we study an infinite horizon game in which pairs of players con nected in a network are randomly matched to bargain players who reach agreement are replaced by new players at the same positions in the network we show that all equilibria are payoff equivalent the payoffs and the set of agreement links converge as players become patient several new concepts mutually estranged sets partners and shortage ratios provide insights into the relative strengths of the positions in the network we develop a procedure to deter mine the limit equilibrium payoffs for all players characterizations of equitable and nondiscriminatory networks are also obtained jel c78 d85 competitive equilibrium theory assumes large and anonymous markets in which every buyer can trade with every seller underlying these assumptions are standard goods and services that may be traded at low transaction costs by agents who are not in specific relationships with one another however in many markets goods and services are heterogeneous e g cars apartments or need to be tailored to particular needs e g manufacturing inputs technical support furthermore trad ing opportunities may depend on transportation costs social relationships infor mation advertising trust technological compatibility joint business opportunities free trade agreements etc in such cases it is natural to model the market using a network where only pairs of connected agents may engage in exchange new theories are needed to explore the influence of the network structure on market outcomes many questions arise how does an agent s position in the net work determine his bargaining power and the local prices he faces who trades with whom and on what terms when are prices uniform in the network one possible conjecture is that an agent s bargaining power is determined by his relative number of connections in the network however this simple theory is implausible consider the network of four sellers located at the top nodes and nine buyers located at the bottom nodes depicted in figure 1 assume that each seller supplies one unit of a homogeneous indivisible good each buyer demands one unit of the good and all buyers have identical values for the good the buyer located in the middle has the largest number of links in the network as he is connected to each

the english auction with differentiated commodities abstract we study economies with indivisibilities that satisfy the gross substitutes gs condition we define an excess demand set with the property that increasing the prices of all goods in excess demand eventually leads to the smallest walrasian prices this procedure is a generalization of the auction studied by g demange d gale and m j sotomayor polit econ 94 1986 863 872 in our auction truthful revelation of demand is a perfect bayesian equilibrium if the smallest walrasian prices correspond to the vickrey clarke groves payments however no dynamic auction can reveal sufficient information to implement the vickrey mechanism if all gs preferences are allowed journal of economic literature classification numbers d4 d44 d5 d51

designing random allocation mechanisms theory and applications randomization is commonplace in everyday resource allocation we generalize the theory of randomized assignment to accommodate multi unit allocations and various real world constraints such as group specific quotas controlled choice in school choice and house allocation and scheduling and curriculum constraints in course allocation we develop new mechanisms that are ex ante efficient and fair in these environments and that incorporate certain non additive substitutable preferences we also develop a utility guarantee technique that limits ex post unfairness in random allocations supplementing the ex ante fairness promoted by randomization this can be applied to multi unit assignment problems and certain two sided matching problems jel c78 d82

competitive equilibria in two sided matching markets with general utility functions we present an exact characterization of utilities in competitive equilibria of two sided matching markets in which the utility of each agent depends on the choice of partner and the terms of the partnership potentially including monetary transfer examples of such markets include sellers and buyers or jobs and workers demange and gale showed that the set of competitive equilibria in this type of market forms a complete lattice with each extreme point of the lattice representing an equilibrium with the highest utilities for the agents on one side and the lowest utilities for the agents on the opposite side our characterization is based on establishing a connection between the competitive equilibria of a market and the competitive equilibria of certain strict subsets of that market each obtained by removing exactly one agent this characterization captures the effect of competition when agents are added to the market or removed from the market it gives a precise procedure for constructing competitive eq

external and budget deficits in some developing countries abstract this paper documents and explains the positive comovement between the external and budget deficits of developing countries for which post 1960 time series data are available first the estimates indicate that the empirical covariance between these deficits is always positive and is statistically significant for many cases second the empirical covariance is close to that predicted from a tractable small open economy overlapping generation model with heterogeneous goods capturing the joint behavior of the external and budget deficits also the predicted covariance is induced by shocks which are closely related to internal conditions such as domestic resources and fiscal policies and to a much lesser extent to external conditions such as the world interest rate real exchange rate and terms of trade

how to efficiently allocate houses under price controls we examine a housing market with price controls and show how the allocation problem can be solved through a price system we demonstrate that the auction of talman and yang 2008 always generates a core allocation thus resulting in a pareto efficient and stable outcome

rental harmony with roommates abstract we prove existence of envy free allocations in markets with heterogenous indivisible goods and money when a given quantity is supplied from each of the goods and agents have unit demands we depart from most of the previous literature by allowing agents preferences over the goods to depend on the entire vector of prices we then show how our theorem may be applied in two related problems existence of envy free allocations in a version of the cake cutting problem and existence of equilibrium in an exchange economy with indivisible goods and money our proof uses shapley s k k m s theorem and hall s marriage lemma

the combinatorial assignment problem approximate competitive equilibrium from equal incomes this paper proposes a new mechanism for combinatorial assignment for example assigning schedules of courses to students based on an approximation to competitive equilibrium from equal incomes ceei in which incomes are unequal but arbitrarily close together the main technical result is an existence theorem for approximate ceei the mechanism is approximately efficient satisfies two new criteria of outcome fairness and is strategyproof in large markets its performance is explored on real data and it is compared to alternatives from theory and practice all other known mechanisms are either unfair ex post or manipulable even in large markets and most are both manipulable and unfair

the hamilton model with a general autoregressive component estimation and comparison with other models of economic time series abstract this paper generalizes the hamilton model to the important case in which the autoregressive component need not contain a unit root using u s quarterly real gnp data the model is estimated and the results are compared to those of hamilton some monte carlo evidence for the model is presented and its in sample forecasting performance is discussed and compared to the original hamilton model the arima model and the deterministic time trend model

some urban facts of life implications for research and policy abstract this review of recent literature explores the challenges to urban food and nutrition security in the rapidly urbanizing developing world the premise of the manuscript is that the causes of malnutrition and food insecurity in urban and rural areas are different due primarily to a number of phenomena that are unique to or exacerbated by urban living these areas include a a greater dependence on cash income b weaker informal safety nets c greater labor force participation of women and its consequences for child care d lifestyle changes particularly diet and exercise patterns e greater availability of public services but questionable access by the poor f greater exposure to environmental contamination and g governance by a new possibly nonexistent set of property rights the main focus is on identifying what is different about urban areas so as to better frame the program and policy responses

the nature of international integration and human resource policies in multinational companies in this article we demonstrate that the literature concerning multinational companies mncs and employment relations has failed to develop a convincing explanation of variation in the extent to which mncs develop a global element to the management of their international workforces we argue that whether mncs have an incentive to develop international human resource policies is shaped by the extent and nature of international integration which we define as the commonalities and inter dependencies in the production process across borders in particular we identify three aspects of the integration of mncs that are crucial in this respect whether the firm pursues financial economies or synergistic linkages from its international operations whether it segments or replicates its operations across countries and whether it standardises or differentiates its product internationally copyright the author 2010 published by oxford university press on behalf of the cambridge political economy society all rights reserved oxford university press

a competitive partnership formation process a group of heterogeneous agents may form partnerships in pairs all single agents as well as all partnerships generate values if two agents choose to cooperate they need to specify how to split their joint value among one another in equilibrium which may or may not exist no agents have incentives to break up any existing partnerships or form new partnerships this paper proposes a dynamic competitive adjustment process that always either finds an equilibrium or exclusively disproves the existence of any equilibrium in finitely many steps when an equilibrium exists partnership and revenue distribution will be automatically and endogenously determined by the process moreover several fundamental properties of the equilibrium solution and the model are derived

trading networks with price setting agents abstract in a wide range of markets individual buyers and sellers trade through intermediaries who determine prices via strategic considerations typically not all buyers and sellers have access to the same intermediaries and they trade at correspondingly different prices that reflect their relative amounts of power in the market we model this phenomenon using a game in which buyers sellers and traders engage in trade on a graph that represents the access each buyer and seller has to the traders we show that the resulting game always has a subgame perfect nash equilibrium and that all equilibria lead to an efficient allocation of goods finally we analyze trader profits in terms of the graph structure roughly a trader can command a positive profit if and only if it has an essential connection in the network thus providing a graph theoretic basis for quantifying the amount of competition among traders

evaluating assignment without transfers a market perspective all random assignments allocations without transfers can be considered as market outcomes with personalized prices and an equal income prices proportional across agents imply efficiency common prices lead to efficiency and envy freeness this market perspective also reveals a weakness of envy freeness

the exposure problem and market design markets have an exposure problem when getting to the optimal allocation requires a sequence of transactions which if started but not completed leaves at least one trader with losses we use laboratory experiments to evaluate the effect of the exposure problem on alternative market mechanisms the continuous double auction performs poorly efficiency is only 20 when exposure is high and 55 when it is low a package market effectively eliminates the exposure problem in low and high exposure treatments efficiency is 82 and 89 respectively building on stability notions from matching theory we introduce the concept of mechanism stability a model of trade that combines mechanism stability with noisy best responses and imperfect foresight explains the difference in market performance finally decentralized bargaining with contingent contracts performs well with perfect information and communication but not in the more realistic case when traders preferences are privately known

the strategy structure of two sided matching markets we study two sided markets in which agents are buyers and sellers or firms and workers or men and women the agents are to form partnerships which provide them with satisfaction and at the same time make monetary transfers e g salaries or dowries the core of this market game is shown to have a particularly nice structure so that precise answers can be given to questions concerning comparative statics and manipulability the idea of using walrasian equilibrium as a mechanism for making allocations with desirable properties of fairness and efficiency has been studied extensively the scheme involves having agents specify their supply and demand functions the competitive equilibria are then calculated and allocations are made accordingly in general this procedure may run into two difficulties first nonuniqueness if there are several equilibria there may be no fair way to decide which one should be implemented and second manipulability if there is only one equilibrium an informed agent may be able to influence it by suitably falsifying his demand data however as we will show here using the walrasian mechanism does work remarkably well for a certain class of important markets these are the matching markets of our title and they include markets for single items like houses where it is assumed that traders do not wish to acquire more than one item they also include labor markets in which it is desired to match workers with jobs at suitable salaries academic markets in which students are to be assigned to educational institutions marriage markets where men and women are matched through negotiating of dowries it turns out that in these markets both the problems of nonuniqueness and manipulability can be resolved in a

multi item auctions a collection of items is to be distributed among several bidders and each bidder is to receive at most one item assuming that the bidders place some monetary value on each of the items it has been shown that there is a unique vector of equilibrium prices that is optimal in a suitable sense for the bidders in this paper we describe two dynamic auction mechanisms one achieves this equilibrium and the other approximates it to any desired degree of accuracy

economic engineering and the design of matching markets the contributions of alvin e roth alvin roth s research on and design of new economic systems has had a wide and large impact on human welfare from the matching of residents to medical programs to the assignment of students to schools to the manner in which kidneys are allocated to patients needing transplants this article discusses his important contributions to the understanding and improvement of matching markets highlighting roth s key roles in some of the most prominent successes of market design and the ascension of economic engineering

multi item vickrey english dutch auctions abstract assuming that bidders wish to acquire at most one item this paper defines a polynomial time multi item auction that locates the vcg prices in a finite number of iterations for any given starting prices this auction is called the vickrey english dutch auction and it contains the vickrey english auction sankaran j k 1994 on a dynamic auction mechanism for a bilateral assignment problem math soc sci 28 143 150 and the vickrey dutch auction mishra d parkes d 2009 multi item vickrey dutch auctions games econ behav 66 326 347 as special cases by means of numerical experiments it is showed that when the auctioneer knows the bidders value distributions the vickrey english dutch auction is weakly faster than the vickrey english auction and the vickrey dutch auction in 89 percent and 99 percent respectively of the investigated problems a greedy version of the vickrey english dutch auction is demonstrated to perform even better in the simulation studies

online ascending auctions for gradually expiring items abstract we consider dynamic auction mechanisms for the allocation of multiple items items are identical but have different expiration times and each item must be allocated before it expires buyers are of dynamic nature and arrive and depart over time our goal is to design mechanisms that maximize the social welfare we begin by showing that dominant strategy incentive compatibility cannot be used in this case since any such auction cannot obtain any constant fraction of the optimal social welfare we then design two auctions that perform well under a wide class of semi myopic strategies for every combination of such strategies the auction is associated with a different algorithm or allocation rule and so we have a family of semi myopic algorithms we show that any algorithm in this family obtains at least 1 3 of the optimal social welfare we also provide some game theoretic justification for acting in a semi myopic way we suggest a new notion of set nash equilibrium where we cannot pinpoint a single best response strategy but rather only a set to which best response strategies belong we show that our auctions have a set nash equilibrium which is all semi myopic

working women in an urban setting traders vendors and food security in accra abstract data collected from a 1997 household survey carried out in accra ghana are used to look at the crucial role that women play as income earners and securing access to food in urban areas one third of the households surveyed are headed by women for all households women s labor force participation is high with 75 of all households having at least one working woman the high number of female headed households and the large percentage of working women in the sample provide a good backdrop for looking at how women earn and spend income differently than men in an urban area livelihood strategies for both men and women are predominantly labor based and dependent on social networks for all households in the sample food is still the single most important item in the total budget yet important and striking differences between men s and women s livelihoods and expenditure patterns exist compared to men women are less likely to be employed as wage earners and more likely to work as street food vendors or petty traders women earn lower incomes but tend to allocate more of their budget to basic goods for themselves and their children while men spend more on entertainment for themselves only despite lower incomes and additional demands on their time as housewives and mothers female headed households petty traders and street food vendors have the largest percentage of food secure households women may be achieving household food security but at what cost this paper explores differences in income expenditure and consumption patterns in an effort to answer this question and suggests ways that urban planners and policy makers can address special concerns to working women in urban areas

informational limitations of ascending combinatorial auctions abstract we study the inherent limitations of natural widely used classes of ascending combinatorial auctions specifically we show that ascending combinatorial auctions that do not use both non linear prices and personalized prices cannot achieve social efficiency with general bidder valuations we also show that the loss of efficiency can be severe and that only a diminishing fraction of the social welfare may be captured this justifies the added complexity in the auctions suggested by e g parkes and ungar 2000 29 and ausubel and milgrom 2002 2

non manipulable house allocation with rent control in many real life house allocation problems rents are bounded from above by price ceilings imposed by a government or a local administration this is known as rent control because some price equilibria may be disqualified given such restrictions this paper proposes an alternative equilibrium concept called rationing price equilibrium tailored to capture the specific features of housing markets with rent control an allocation rule that always selects a rationing price equilibrium is defined and it is demonstrated to be constrained efficient and group non manipulable for almost all preference profiles in its bounding cases the rule reduces to a number of well known mechanisms from the matching literature in this sense the housing market with rent control investigated in this paper integrates several of the predominant matching models into a more general framework

connecting the cooperative and competitive structures of the multiple partners assignment game multiple partners assignment game is the name used by sotomayor the multiple partners game in m majumdar ed equilibrium and dynamics essays in honor of david gale the macmillan press ltd new york 1992 the lattice structure of the set of stable outcomes of the multiple partners assignment game int j game theory 28 1999 567 583 to describe the cooperative structure of the many to many matching market with additively separable utilities stability concept is proved to be different from the core concept an economic structure is proposed where the concept of competitive equilibrium payoff is introduced in connection to the equilibrium concept from standard microeconomic theory the paper examines how this equilibrium concept compares with the cooperative equilibrium concept properties of interest to the cooperative and competitive markets are derived

fair allocation of indivisible goods and criteria of justice a set of n objects and an amount m of money is to be distributed among m people example the objects are tasks and the money is compensation from a fixed budget an elementary argument via constrained optimization shows that for m sufficiently large the set of efficient envy free allocations is nonempty and has a nice structure in particular various criteria of justice lead to unique best fair allocations that are well behaved with respect to changes of m this is in sharp contrast to the usual fair division theory with divisible goods