does exchange rate variability depress trade flows evidence from error correction models this paper examines the impact of exchange rate volatility on the trade flows of the g 7 countries in the context of a multivariate error correction model the error correction models do not show any sign of parameter instability the results indicate that the exchange rate volatility has a significant negative impact on the volume of exports in each of the g 7 countries assuming market participants are risk averse these results imply that exchange rate uncertainty causes them to reduce their activities change prices or shift sources of demand and supply in order to minimize their exposure to the effects of exchange rate volatility this in turn can change the distribution of output across many sectors in these countries it is quite possible that the surprisingly weak relationship between trade flows and exchange rate volatility reported in several previous studies are due to insufficient attention to the stochastic properties of the relevant time series copyright 1993 by mit press

nonlinear effects of exchange rate volatility on the volume of bilateral exports in this paper we investigate empirically the impact of exchange rate volatility on real international trade flows utilizing a 13 country data set of monthly bilateral real exports for 1980 1998 we compute one month ahead exchange rate volatility from the intra monthly variations in the exchange rate to better quantify this latent variable we find that the effect of exchange rate volatility on trade flows is nonlinear depending on its interaction with the importing country s volatility of economic activity and that it varies considerably over the set of country pairs considered copyright 2003 john wiley sons ltd

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

job matching under constraints studying job matching in a kelso crawford framework we consider arbitrary constraints imposed on sets of doctors that a hospital can hire we characterize all constraints that preserve the substitutes condition for all revenue functions that satisfy the substitutes condition a critical condition on hospitals revenue functions for well behaved competitive equilibria a constraint preserves the substitutes condition if and only if it is a generalized interval constraint which specifies the minimum and maximum numbers of hired doctors forces some hires and forbids others additionally generalized polyhedral constraints are precisely those that preserve the substitutes condition for all group separable revenue functions

comparing optima do simplifying assumptions affect conclusions consider a family of maximization models in which the optimum trades off beneficial and costly effects then comparative statics derived under many kinds of simplifying assumptions about the benefits technology are also true for general convex and nonconvex technologies for example any comparative statics conclusion about investment by a risk averse decision maker under uncertainty that holds when expected returns are described by a general linear function also holds for an arbitrary nonlinear expected return function

multi item vickrey dutch auctions descending price auctions are adopted for goods that must be sold quickly and in private values environments for instance in flower fish and tobacco auctions in this paper we introduce ex post efficient descending auctions for two environments multiple non identical items and buyers with unit demand valuations and multiple identical items and buyers with non increasing marginal values our auctions are designed using the notion of universal competitive equilibrium uce prices and they terminate with uce prices from which the vickrey payments can be determined for the unit demand setting our auction maintains linear and anonymous prices for the homogeneous items setting our auction maintains a single price and adopts ausubel s notion of clinching to compute the final payments dynamically the auctions support truthful bidding in an ex post nash equilibrium and terminate with an ex post efficient allocation in simulation we illustrate the speed and elicitation advantages of these auctions over their ascending price counterparts

exchange rate volatility and foreign trade evidence from thirteen ldc s this article investigates empirically the impact of real exchange rate volatility on the export flows of 13 less developed countries ldc s over the quarterly period 1973 1996 estimates of the cointegrating relations are obtained using johansen s multivariate procedure estimates of the short run dynamics are obtained for each country using the error correction technique the major results show that increases in the volatility of the real effective exchange rate approximating exchange rate uncertainty exert a significant negative effect on export demand in both the short run and the long run in each of the 13 ldc s these effects may result in significant reallocation of resources by market participants

bundling equilibrium in combinatorial auctions this paper analyzes ex post equilibria in the vcg combinatorial auctions if is a family of bundles of goods the organizer may restrict the bundles on which the participants submit bids and the bundles allocated to them to be in t he vcg combinatorial auctions obtained in this way are known to be truth telling mechanisms in contrast this paper deals with non restricted vcg auctions in which the buyers choose strategies that involve bidding only on bundles in and these strategies form an equilibrium we fully characterize those that induce an equilibrium in every vcg auction and we refer to the associated equilibrium as a bundling equilibrium the main motivation for studying all these equilibria and not just the domination equilibrium is that they afford a reduction of the communication complexity we analyze the tradeoff between communication complexity and economic efficiency of bundling equilibrium

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

a competitive market model for indivisible commodities abstract a general competitive market model for trading indivisible goods is introduced there are a group of traders and several indivisible goods each trader is initially endowed with several units of each indivisible good and some amount of money traders have preferences over the bundle of indivisible goods and the quantity of money they consume it is shown that the market has a walrasian equilibrium if and only if an associated linear program problem has an optimal solution with its value equal to the potential market value and that the equilibrium prices of the goods and the profits of the traders are the optimal solutions of the linear program problem

stability in large matching markets with complementarities labor markets can often be viewed as many to one matching markets it is well known that if complementarities are present in such markets a stable matching may not exist we study large random matching markets with couples we introduce a new matching algorithm and show that if the number of couples grows slower than the size of the market a stable matching will be found with high probability if however the number of couples grows at a linear rate with constant probability not depending on the market size no stable matching exists our results explain data from the market for psychology interns

the ethnic wage gap and employment differentials in the 1990s evidence for britain abstract it is twenty years since britain passed legislation to combat racial discrimination despite this britain s nonwhite ethnic minorities still appear to face substantial amounts of discrimination in the labour market unemployment is particularly severe

the earnings of male immigrants in england evidence from the quarterly lfs in this paper we estimate earnings functions for native born and foreign born white and non white males in the english labour market using data from the quarterly labour force survey our results highlight the importance of distinguishing between native born and foreign born males when investigating the labour market experience of ethnic minorities furthermore the earnings performance amongst white immigrants varies considerably

the effects of exchange rate volatility on exports some new estimates investigations of the impact of exchange rate volatility on exports have not allowed for the integrated non stationary of the variables employed in estimation the results reported in this note are suggestive that in the context of an error correction framework real exchange rate volatility has a significant impact on exports

exchange rate uncertainty and agricultural trade using a sample of bilateral trade flows across ten developed countries between 1974 and 1995 this article explores the effect of exchange rate uncertainty on the growth of agricultural trade as compared to other sectors based on a gravity model that controls for other factors likely to determine bilateral trade the results show that real exchange rate uncertainty has had a significant negative effect on agricultural trade over this period moreover the negative impact of uncertainty on agricultural trade has been more significant compared to other sectors

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

matching with couples stability and incentives in large markets accommodating couples has been a longstanding issue in the design of centralized labor market clearinghouses for doctors and psychologists because couples view pairs of jobs as complements a stable matching may not exist when couples are present this paper s main result is that a stable matching exists when there are relatively few couples and preference lists are suciently short relative to market size we also discuss incentives in markets with couples we relate these theoretical results to the job market for psychologists in which stable matchings exist for all years of the data despite the presence of couples

bertrand competition for inputs and walrasian outcomes market making by merchants who obtain stock from suppliers and resell it to con sumers is modeled as a two stage pricing game with winner take all c ompetition for the inputs in contrast to fixed capacity models the re is a unique subgame perfect nash equilibrium spne which is walr asian for elastic demand and non walrasian for inelastic demand alte rnatively when merchants first sell forward contracts to consumers a nd then compete for supplies the unique spne is always walrasian th us the author has an equilibrium model in which walrasian price aris es not from the benevolent actions of a fictitious auctioneer but fr om optimal price setting behavior of merchants copyright 1988 by american economic association

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

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

identifying combinatorial valuations from aggregate demand abstract we study identification of combinatorial valuations from aggregate demand each utility function takes as arguments subsets or alternatively quantities of the multiple goods we exploit mathematical insights from auction theory to generically identify the distribution of utility functions in our setting aggregate demand for each item is observable while demand for bundles is not nevertheless our identification result allows us to recover the latter

reconsidering carbon permits auction mechanism an efficient dynamic model one of major concerns for china and developing countries is the new international trade rule concerning carbon emissions which one needs to know its suitable mechanism and the possible implication on china s carbon trading market precisely in an emission and trade scheme an important question is whether the auction outcome is efficient since this is closely related with the economic costs of emissions reduction due to the unique features of carbon permits existing auction mechanisms do not seem to be suitable for their distribution inspired by the t tonnement process this paper proposes a new auction mechanism for them for both practical application and theoretical extension the discrete and continuous situations are examined respectively the result shows that the proposed auction converges to pareto optimal equilibria and that without ties the equilibrium is unique for bidders the straightforward bidding strategy is the most preferred one in the sense that the strategy makes them avoid the risk of loss intuitively the auctioneer s utility is increasing in the number of bidders while bidders pay off is increasing in permits to a certain extent the proposed auction mechanism resolves the confliction between efficiency and revenue in the multi item auction theory while it increases people s understanding for carbon emission auction mechanism design

appropriation and efficiency a revision of the first theorem of welfare economics the first theorem of welfare economics rests on the assumption that individuals have neither price making nor market making capacities we offer a revision in which individuals have such capacities the revision emphasizes two keys for market efficiency i the need to align private rewards with social contributions called full appropriation and ii the need for an assumption to counter the possibility of coordination failures in the choice of produced commodities called noncomplementarity we also emphasize that information about prices of unmarketed commodities involves decentralized knowledge available only to product innovators and that pecuniary extemalities are important potential sources of market failure jel d51 d60 d62

matching with contracts comment the theory of two sided matching markets has interested researchers for its theoretical appeal and its relevance to the design of real world institutions the medical residency matching mecha nism in the united states the national resident matching program nrmp and student assign ment systems in new york city and boston are important mechanisms designed by economists using the theory 1 hatfield and paul r milgrom 2005 present a unified framework of matching with contracts which includes the two sided matching and package auction models as well as a simplified version of a labor market model of alexander kelso and vincent p crawford 1982 as special cases they introduce the substitutes condition of contracts which is an adaptation of the substitutability condition in the matching literature roth and marilda a oliveira sotomayor 1990 to matching with contracts they show that there exists a stable allocation if contracts are substitutes for hospitals and that a number of other results in matching generalize to problems with contracts they further claim that the substitutes condition on individual hospitals prefer ences is necessary to guarantee the existence of a stable allocation for all possible singleton preferences of others that is if contracts are not substitutes for a hospital then there exists a preference profile of other hospitals with single job openings and doctors such that there exists no stable allocation we show that this last claim of hatfield and milgrom 2005 does not hold in general the counterexample we present involves a hospital which has two different kinds of positions and the preferences of the hospital are a combination of preferences of these two positions while the substitutes condition does not hold for that hospital we adopt a technique developed by bettina klaus and flip klijn 2005 and show that there exists a stable allocation we then present the weak substitutes condition which we show is necessary to guarantee existence of stable allocations the modified result we present as well as the original contribu tion of hatfield and milgrom 2005 suggest a connection between the substitutes condition and stability 2

the effect of false name bids in combinatorial auctions new fraud in internet auctions we examine the effect of false name bids on combinatorial auction protocols false name bids are bids submitted by a single bidder using multiple identifiers such as multiple e mail addresses the obtained results are summarized as follows 1 the vickrey clarke groves vcg mechanism which is strategy proof and pareto efficient when there exists no false name bid is not falsename proof 2 there exists no false name proof combinatorial auction protocol that satisfies pareto efficiency 3 one sufficient condition where the vcg mechanism is false name proof is identified i e the concavity of a surplus function over bidders

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

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

contracts versus salaries in matching a general result abstract it is shown that a matching market with contracts can be embedded into a matching market with salaries under weaker conditions than substitutability of contracts in particular the result applies to the recently studied problem of cadet to branch matching as an application of the embedding result a new class of mechanisms for matching markets with contracts is defined that generalize the firm proposing deferred acceptance algorithm to the case where contracts are unilateral substitutes for firms

real exchange rate volatility and international trade a reexamination of the theory one of the issues that have received considerable attention in the comparison of the properties of alternative exchange rate regimes is the effect of exchange rate risk on the volume of trade it has been argued that the higher volatility of exchange rates witnessed since the adoption of the floating regime in 1973 has led to a decrease in international trade transactions this is because most trade contracts are not for immediate delivery of goods and since they are denominated in terms of the currency of either the importer or the exporter unanticipated fluctuations in the exchange rate affect realized profits and hence the volume of trade it is implicitly assumed that forward exchange markets that can help traders eliminate this type of variations in profits either are not available as it is true for the majority of currencies because most are not fully convertible thereby impairing forward markets or for some reason they are not utilized to fully hedge exchange risk present in trade transactions the empirical evidence regarding the effect of exchange rate risk on trade has at best been inconclusive the large majority of the empirical studies are unable to establish a systematically significant link between exchange rate variability and the volume of international trade whether on an aggregate or on a bilateral basis abrams 1 akhtar and hilton 2 cushman 4 5 6 and kenan and rodrik 12 find some significant negative effects of exchange volatility on exports however bailey tavlas and uhlan 3 hooper and kohlhagen 10 and an international monetary fund study 11 do not find any supporting evidence for the depressing effect of exchange rate volatility on international trade it is also interesting to note that in many of these studies a significant positive effect of exchange rate volatility on the volume of trade is found for some cases however the positive effect believed to be at odds with the theory was either ignored or dismissed as a perverse result since as far as volumes are concerned theoretical considerations

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

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

an economic perspective on auctions the recent spectrum auctions in europe have shown that serious problems can wise in auctions where multiple complementary objects are being sold such as blocks of radio spectrum that will subsequently be used by the wining bidders to compete against each other in downstream markets other important instances of such situations include take off and landing slots at airports and rights for electricity and gas transmission t i first review some of the theory describing multi object auctions i i next outline the importance of strategic effects arising in auctions that are followed by competition between the bidders and the tension arising between various goals such as efficiency and revenue maximization although more flexible auction formats can have virtues particularly in taking into account complementarities they can also be manipulated by bidders to build market power to the detriment of consumers we next apply these insights to the recent european umts licence auctions finally we draw the main conclusions and policy implications

exchange rate volatility and international trade the purpose of this note is to show that a positive effect of exchange rate volatility on export production has a theoretical basis the key to this claim is that as the exchange rate volatility increases so does the value of the real option to export to the world market higher volatility increases the potential gains from trade this may explain part of the mixed empirical findings regarding the effects of exchange rate risk on international trade

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

bayesian incentive compatibility via matchings abstract optimally allocating cellphone spectrum advertisements on the internet and landing slots at airports is computationally intractable when the participants may strategize not only must the optimizer deal with complex feasibility constraints but also with complex incentive constraints we give a very simple method for constructing a bayesian incentive compatible mechanism from any potentially non optimal algorithm that maps agents reports to an allocation the expected welfare of the mechanism is approximately at least that of the algorithm on the agents true preferences the construction is based on a maximum weight matching in the type space of each agent that be calculated quickly when the type spaces are reasonably sized furthermore the computation can be performed independently for each agent and therefore scales well with the number of agents a similar construction was previously given by hartline and lucier 2010 for agents with single dimensional types ours allows multi dimensional types

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

are exports a monotonic function of exchange rate volatility evidence from disaggregated pork exports production and marketing lags in agri food supply chains often force agricultural producers and food processors to commit to output targets before prices and exchange rates are realized a theoretical model illustrates how the processor s degree of risk aversion and domestic sales may cause the relationship between volatility of the exchange rate and exports to be non monotonic the relationship between exchange rate volatility and quebec pork exports to the united states and japan is investigated using linear and non linear estimation methods the results support the hypothesis that the relationship between exports and volatility is non monotonic

an analysis of the male racial earnings differential in the uk using the general household survey 1986 an analysis of the male racial earnings differential in the uk using the general household survey applied economics vol 18 no 11 pp 1233 1242

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

an equilibrium analysis of the simultaneous ascending auction we provide a bayes nash equilibrium analysis of the simultaneous ascending auction saa when local bidders interested in a single item compete against global bidders interested in aggregating many items we first assume that each local bidder values only a specific item e g the license for the region where it has monopoly power and that global bidders valuation functions are convex for this environment we show that a global bidder faces an exposure problem with adverse consequences for revenue and efficiency in the limit when the number of items grows large the saa is revenue and efficiency equivalent to the vickrey clarke groves vcg mechanism we extend our analysis to include the case where items are substitutes for local bidders so that price arbitrage will occur as observed in many spectrum auctions this environment which combines substitutes and complements results in an aggravated exposure problem consequently the saa is no longer efficient and may yield dramatically lower revenues than the vcg mechanism finally we relax the assumption that global bidders valuation functions are convex by considering an environment with medium sized global bidders who demand fewer than all items we show that global bidders divide the market at low prices when market sharing is feasible while they engage in mutually destructive bidding when there is a fitting problem in both cases the saa again underperforms relative to the vcg mechanism

stability and auctions in labor markets with job security fu et al 2016 introduced a stability concept for labor markets with job security we show that their proposed outcomes form nash equilibria of an auction where firms compete for workers this parallels literature on stable outcomes and similar auctions and yields new price of anarchy bounds

the vulnerability of price stabilization schemes to speculative attack this paper examines the effects of government attempts to stabilize the prices of commodities by use of buffer stocks agricultural goods subject to supply uncertainty as well as depletable resources are considered in each case it is shown that the resulting rational expectations competitive equilibrium contains a speculative attack a situation where the entire government stock is suddenly purchased by previously inactive speculators the analysis is applied to the historical attempt to peg the gold price which caused the attack of 1968 the insights gained and the methodology developed also apply to the various international agreements to impose bans on commodity prices which have been proposed by the united nations conference on trade and development

labor market discrimination against hispanic and black men h ispanic american men have lower average wage rates than white non hispanics in 1975 the average white non hispanic male wage earner in the united states earned 5 97 an hour mexican men earned 4 31 72 as much as white non hispanics puerto rican men earned 4 52 76 as much and cuban men earned 5 33 89 as much as white non hispanics by way of comparison black men s average wages in 1975 were 4 65 78 of the white male wage several possible reasons for the hispanics lower wages come to mind among them are age and education geographic location immigration language difficulties and discrimination for example as shown in table 1 mexicans and puerto ricans are younger on average than the white non hispanic population and earnings tend to rise with age hispanics have lower average levels of education than white non hispanics and wages are positively associated with education many mexican americans live in the southwest where prices are relatively low moreover hispanics are more likely to be recent immigrants and to lack fluency in english than white non hispanics and so to be at a disadvantage in the labor market in addition there is a widespread belief that hispanics suffer from employment discrimination and cannot obtain the wages that their human capital would command if they were non hispanic whites how much of the wage differentials described above are due to each of these factors and to other inter group differences in wage related characteristics in particular how much impact does labor market discrimination have on the average hispanic man s wage and how does this compare with discrimination against blacks this paper provides answers to these questions a few other efforts have been made to analyze the relative earnings of hispanic and white nonhispanic men using 1960 and 1970 census data fogel 1966 poston and alvirez 1973 poston alvirez and tienda 1976 long 1977 and gwartney and long 1978 we use more recent data from the 1976 survey of income and education this data set enables us to measure wage rates more accurately and to specify the wage function more completely than does the census unlike previous analysts in estimating the wage function we take account of possible selectivity bias due to the distinction between average wage offers and average observed wages thus we hope to obtain a more accurate and up to date measure of labor market discrimination against hispanic men section ii explains the method used to separate the minority white non hispanic wage differential into the portions due to differences in average characteristics and the portion due to differences in unobserved factors and discrimination taking into account the possibility of selectivity bias in the observed wage sample section iii describes the data used in the study and the specification of the wage equation the breakdown of the observed wage differentials into components due to differences in participation in the wage and salary sector local price levels average characteristics and discrimination are presented in section iv section v summarizes our findings and discusses their implications for efforts to improve the economic situation of hispanics in the united states

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

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

mechanisms for a spatially distributed market abstract we consider the problem of a spatially distributed market with strategic agents a single good is traded in a set of independent markets where shipment between markets is possible but costly the problem has previously been studied in the non strategic case in which it can be analyzed and solved as a min cost flow problem we consider the case where buyers and sellers are strategic our first result gives a double characterization of the vcg prices first as distances in a certain residue graph and second as the minimal for buyers and maximal for sellers equilibrium prices this provides a computationally efficient individually rational and incentive compatible welfare maximizing mechanism this mechanism is necessarily not budget balanced and we also provide a budget balanced mechanism which is also computationally efficient incentive compatible and individually rational that achieves high welfare finally we present results for some extensions of the model

iterative auction design for tree valuations we study a special class of multi item valuations tree valuations that exhibit both value complementarity and substitutability we provide a linear programming formulation of the efficient allocation problem that is of polynomial size in the number of agents and items this reveals a new class of valuations for which a walrasian equilibrium exists in the presence of value complementarities an iterative algorithm for this linear program in conjunction with an appropriate payment rule yields an iterative auction that implements the efficient outcome at an ex post perfect equilibrium this auction relies on a simple pricing rule compact demand reports and uses a novel interleaved price update structure to assign final payments to bidders that guarantee truthful bidding

gender race pay and promotion in the british nursing profession estimation of a generalized ordered probit model we analyse job grading within the uk national health service nursing profession using 1994 survey data we start from the ordered probit model for which we develop and apply appropriate specification tests threshold constancy and covariate exogeneity are rejected with important consequences for estimates of the influence of gender ethnicity training and career interruptions we find little evidence of disadvantage for females relative to males but significant differences in speed of promotion between ethnic groups implying non negligible differences in lifetime earnings copyright 2000 john wiley sons ltd

the employment of married women in the united kingdom 1970 83 the proportion of married women in employment in the united kingdom grew rapidly during the 1970s rising from around 50 to 60 per cent the paper investigates this change using a time series of cross sections from the family expenditure survey an attempt is made to assess how much of the change was due to trends in the observable characteristics of the population and what part was played by changes in behavioural and other factors reflected in the coefficients of the model a technique of growth accounting is proposed and used to this purpose excerpt

the impact of exchange rate volatility on international trade flows despite the best efforts of economists a basic paradox as to the impact of exchange rate volatility on trade flows remains unresolved at both the theoretical and empirical level this paper surveys the vast literature in the area in an attempt to identify major issues which have contributed to the development of the debate and examine whether any general direction for consensus may be found

package auctions and exchanges we report recent advances concerning the package allocation problem in which traders seek to buy or sell combinations of goods the problems are most difficult when some goods are not substitutes in that case competitive equilibrium typically fail to exist but the core is non empty and comprises the competitive solutions also in that case the vickrey auction fails to select core allocations and yield revenues that are less than competitive the ausubel milgrom auction generally selects core allocations and when goods are substitutes prescribes the vickrey allocation we also evaluate the problems and promise of mechanisms for the package exchange problem

a double sided multiunit combinatorial auction for substitutes theory and algorithms combinatorial exchanges have existed for a long time in securities markets in these auctions buyers and sellers can place orders on combinations or bundles of different securities these orders are conjunctive they are matched only if the full bundle is available on business to business b2b exchanges buyers have the choice to receive the same product with different attributes for instance the same product can be produced by different sellers a buyer indicates his preference by submitting a disjunctive order where he specifies the quantity he wants of each particular good and what limit price he is willing to pay for each good thus providing a subjective valuation of each attribute only the goods with the best prices will be traded this article considers a doubled sided multiunit combinatorial auction for substitutes that is a uniform price auction where buyers and sellers place both types of orders conjunctive and orders and disjunctive xor orders we show that linear competitive prices exist we also propose an algorithm to clear the market which is particularly efficient when the number of traders is large and the goods are divisible

price controls non price quality competition and the nonexistence of competitive equilibrium we investigate how price ceilings and floors affect outcomes in continuous time double auction markets with discrete goods and multiple qualities when price controls exist the existence of competitive equilibria is no longer guaranteed hence we investigate the nature of non price competition and how markets might evolve in its presence we develop a quality competition model based on matching theory equilibria of the quality competition model always exist in such price constrained markets moreover they naturally correspond to competitive equilibria when competitive equilibria exist additionally we characterize the set of equilibria of the quality competition model in the presence of price restrictions in a series of experiments we find that market outcomes closely conform to the predictions of the model in particular price controls induce non price competition between agents both in theory and in the experimental environment market behaviors result in allocations close to the predictions of the model

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

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

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

black white male earnings and employment prospects in the 1970s and 1980s evidence for britain abstract using a sample of around 80 000 whites and 2500 blacks the paper highlights not just the economic disadvantage of blacks but also that this disadvantage worsened in the 1980s in britain