the strategy proof provision of public goods under congestion and crowding preferences we examine the strategy proof provision of excludable public goods when agents care not only about the level of provision of a public good but also the number of consumers we show that on such domains strategy proof and efficient social choice functions satisfying an outsider independence condition must be rigid in that they must always assign a fixed number of consumers regardless of individual desires to participate the fixed number depends on the attitudes of agents regarding group size being small when congestion effects dominate individuals prefer to have fewer other consumers and large when cost sharing effects dominate agents prefer to have more consumers a hierarchical rule selects which consumers participate and a variation of a generalized median rule to selects the level of the public good under heterogeneity in agents views on the optimal number of consumers strategy proof efficient and outsider independent social choice functions are much more limited and in an important case must be dictatorial

a short proof for the characterization of the core in housing markets we provide a short proof for the following characterization of the core in housing markets first proved by ma 1994 the core is the only rule that satisfies strategy proofness pareto efficiency and individual rationality

group incentive compatibility in a market with indivisible goods abstract in a market where each trader has one unit of an indivisible good there are procedures for exchanging goods which result in competitive allocations one of these procedures the top trading cycle has the property that it is in each trader s best interest to report his true preferences over the set of goods this note shows that no subset of traders can misrepresent their preferences and improve the allocation for all members of the subset additionally if there are no indifferences in the preferences then some traders in a subset that misrepresents preferences do worse

the walking debt crisis abstract this article sheds light on the question whether arising sovereign credit risk in the emu has been triggered by the us subprime crunch by adapting recent econometric methodologies suggested in the related field of speculative bubbles we find clear evidence for fast diverging and even explosive behavior of emu government bond yields of peripheral countries relative to germany during the financial and the european debt crisis this might be caused by flight to quality effects to german government bonds coincident with the collapse of lehman brothers and by a loss of confidence in the fiscal stability of greece ireland italy portugal and spain during the european debt crisis first we find compelling evidence for bubbles in the dow jones equity real estate investment trusts reits index which serves as a weekly measure of economic activity in the north american real estate sector second in our main analysis we test whether the collapsing bubble in the housing market triggered the diverging government bond yields during two crisis regimes our findings indicate that this was the case in the course of the financial crisis but not during the emu sovereign debt crisis these results suggest that the severe fiscal problems in peripheral countries are homemade rather than imported from the us

efficient resource allocation on the basis of priorities many institutions allocate resources by non market mechanisms based on priorities in this paper we introduce a model of resource allocation on the basis of priorities and address the following questions is it possible to allocate resources on the basis of any priority structure if yes when can we do this pareto efficiently without creating incentives for manipulation and consistently across different groups of agents and resource levels we adopt a basic indivisible objects model with a finite number of object types and a finite quota of goods of each type some interesting examples are the determination of access to education allocation of graduate houses offices or tasks agents are assumed to have strict preferences over object types and remaining unassigned an assignment is an allocation of the objects to the agents such that every agent receives at most one object a rule associates an assignment to each preference profile we formalize a priority structure to be a collection of strict priority rankings of individuals indexed by the object types where i a j would be read as i has higher priority for object a than j we assume that the priority structure is exogenously fixed and allow the preferences of the agents to vary a rule is said to violate a priority of i for a if there is a preference profile under which i envies j who is assigned a and publication information econometrica 70 6 november 2002 2489 2497 the copyright to this article is held by the econometric society http www econometricsociety org it may be downloaded printed and reproduced only for personal or classroom use absolutely no downloading or copying may be done for or on behalf of any for profit commercial firm or other commercial purpose without the explicit permission of the econometric society for this purpose contact julie p gordon executive director of the society at jpg northwestern edu i would like to thank faruk gul wolfgang pesendorfer the co editor the four anonymous referees and the participants of the micro theory lunch seminar in princeton university for their comments and suggestions

on two competing mechanisms for priority based allocation problems we consider the priority based allocation problem there is a set of indivisible objects with multiple supplies e g schools with seats and a set of agents e g students with priorities over objects e g proximity of residence area we study two well known and competing mechanisms the agentoptimal stable mechanism aosm allots objects via the deferred acceptance algorithm the top trading cycles mechanism ttcm allots objects via gale s top trading cycles algorithm we show that the two mechanisms are equivalent or ttcm is fair i e respects agents priorities or resource monotonic o rpopulation monotonic if and only if the priority structure is acyclic furthermore if aosm fails to be efficient consistent for a problem ttcm also fails to be fair consistent for it however the converse is not necessarily true

stable and efficient resource allocation under weak priorities abstract we study the indivisible object allocation problem without monetary transfer in which each object is endowed with a weak priority ordering over agents it is well known that stability is generally not compatible with efficiency we characterize the priority structures for which a stable and efficient assignment always exists as well as the priority structures that admit a stable efficient and group strategy proof rule while house allocation problems and housing markets are two classic families of allocation problems that admit a stable efficient and group strategy proof rule any priority augmented allocation problem with more than three objects admits such a rule if and only if it is decomposable into a sequence of subproblems each of which has the structure of a house allocation problem or a housing market

contagion during the greek sovereign debt crisis abstract we examine the impact of news about greece and news about a greek bailout on bank stock prices in 2010 using data for 48 european banks we identify the twenty days with extreme returns on greek sovereign bonds and categorise the news events during those days into news about greece and news about the prospects of a greek bailout we find that except for greek banks news about greece does not lead to abnormal returns while news about a bailout does even for banks without any exposure to greece or other highly indebted euro countries this finding suggests that markets consider news about the bailout to be a signal of european governments willingness in general to use public funds to combat the financial crisis sovereign bond prices of portugal ireland and spain respond to both news about greece and news about a greek bailout

safe haven or contagion the disparate effects of euro zone crises on non euro zone neighbours abstractwhile there have been many studies that examine contagion within the euro zone this article investigates the potential contagion from changes in the greek sovereign risk premium over 2009 2016 as measured by the yield on 10 year government bonds to six european countries outside of the euro zone all of which operated a managed float against the euro we find evidence of contagion to potential euro zone ascendants czech republic hungary and poland but flight to safety or safe haven effects for the united kingdom sweden and switzerland

strategy proof exchange we consider the allocation of goods in exchange economies with a finite number of agents who may have private information about their preferences in such a setting standard allocation rules such as walrasian equilibria or rational expectations equilibria are not compatible with individual incentives we characterize the set of allocation rules which are incentive compatible or in other words the set of strategy proof social choice functions social choice functions which are strategy proof are those which can be obtained from trading according to a finite number of pre specified proportions the number of proportions which can be accommodated is proportional to the number of agents such rules are necessarily inefficient even in the limit as the economy grows

evaluating interval forecasts a complete theory for evaluating interval forecasts has not been worked out to date most of the literature implicitly assumes homoskedastic errors even when this is clearly violated and proceed by merely testing for correct unconditional coverage consequently i set out to build a consistent framework for conditional interval forecast evaluation which is crucial when higher order moment dynamics are present the new methodology is demonstrated in an application to the exchange rate forecasting procedures advocated in risk management

competitive equilibria in school assignment abstract top trading cycles was originally developed as an elegant method for finding a competitive equilibrium of shapley and scarf s housing market we extend the definition of a competitive equilibrium to the school assignment problem and show that there remains a profound relationship between top trading cycles and a competitive equilibrium specifically in every competitive equilibrium with weakly decreasing prices the equilibrium assignment is unique and exactly corresponds to the top trading cycles assignment this provides a new way of interpreting the worth of a student s priority at a given school it also provides a new way of explaining top trading cycles to students and a school board

econometric issues in the analysis of contagion this paper presents a canonical econometric model of contagion and investigates the conditions under which contagion can be distinguished from inter dependence in a two country market set up it is shown that for a range of fundamentals the solution is not unique and for sufficiently large values of the contagion coefficients it has interesting bifurcation properties with bimodal density functions the extension of the model to herding behaviour is also briefly discussed to identify contagion effects in the presence of inter dependencies the equations for the individual markets or countries must contain country market specific forcing variables this sheds doubt on the general validity of the correlation based tests of contagions recently proposed in the literature which do not involve any country market specific fundamentals finally we show that ignoring inter dependence can introduce an upward bias in the estimate of the contagion coefficient and using monte carlo experiments we further show that this bias could be substantial

strategy proof assignment on the full preference domain we consider the problem of efficiently allocating several indivisible objects between agents who are to receive at most one object and whose preferences are private information we examine this standard assignment problem from the perspective of mechanism design giving up the usual assumption of linear preferences and instead using a full preference domain with indifferences permitted we characterize two classes of mechanisms i bi polar serially dictatorial rules by essential single valuedness pareto indifference strategy proofness and non bossiness and ii all selections from bi polar serially dictatorial rules by single valuedness efficiency strategy proofness and weak non bossiness we compare the outcomes from the bi polar serially dictatorial rules with the outcomes obtained using a market based approach namely the core of the market we show that all strongly efficient outcomes in the core can be generated using serially dictatorial rules moreover we argue that serially dictatorial rules have an advantage over the market based approach in that they yield strongly efficient solutions for all preference profiles making it possible to use randomization to restore equity when preferences are private information this type of ex ante equity cannot be implemented using the market based approach

strategy proof house allocation with price restrictions abstract this paper considers a house allocation problem with no initial ownership and where prices are bounded from below and above by exogenously given price restrictions this type of housing market contains e g the assignment market and the student placement problem as special cases a mechanism called the minimal rpe mechanism is defined and two main results are obtained first it is demonstrated that the mechanism is manipulable at some profile in the full preference domain r second it is proved that there is a subset r r of the full domain containing almost all profiles in r such that the minimal rpe mechanism is strategy proof in that subset

competitive fair division several indivisible goods are to be divided among two or more players whose bids for the goods determine their prices an equitable assignment of the goods at competitive prices is given by a fair division procedure called the gap procedure that ensures 1 nonnegative prices that never exceed the bid of the player receiving the good 2 pareto optimality though coupled with possible envy 3 monotonicity such that higher bids never hurt in obtaining a good 4 sincere bids that preclude negative utility and 5 prices that are partially independent of the amounts bid as in a vickrey auction a variety of applications are discussed

the equitable top trading cycles mechanism for school choice the equitable top trading cycles mechanism a particular adaptation of gale s top trading cycles ttc procedure applied to school choice the so called ttc mechanism has attracted much attention both in theory and practice due to its superior efficiency and incentive features we discuss and introduce alternative adaptations of gale s original procedure that can offer improvements over ttc in terms of equity along with various other distributional considerations instead of giving all the trading power to those students with the highest priority for a school we argue for the distribution of the trading rights of all slots of each school this allows them to trade in a thick market where additional constraints can be accommodated by choosing an appropriate pointing rule we propose a particular mechanism of this kind the equitable top trading cycle ettc mechanism which is also pareto efficient and group strategy proof just like ttc and eliminates avoidable justified envy situations ettc generates significantly fewer justified envy situations than ttc both in simulations and the lab

cattle cycles is there a role for a financial accelerator the hypotheses that endogenous credit constraints based on fluctuating asset values and cash flow prolong and accentuate us cattle cycles and that more diversified cow calf firms are less affected by this phenomenon are tested breeding cattle inventories are an interesting example to study credit constraints because they are among the most cyclical of economic time series firms have heterogeneous diversification levels and they avoid many of the problems with previous investment cash flow sensitivities studies noted by kaplan and zingales the results are consistent with earlier credit constraint studies i e breeding cattle inventories are sensitive to shifting credit constraint regimes and cow calf firms with higher diversification levels are less affected by credit constraints

learning matters reappraising object allocation rules when agents strategically investigate individuals form preferences through search interviews discussion and investigation in a stylized object allocation model we characterize the equilibrium learning strategies induced by different allocation rules and trace their welfare consequences our analysis reveals that top trading cycles rules dominate serial priority rules under inequality averse measures of social welfare

house allocation with transfers we consider the shapley scarf house allocation problem where monetary transfers are allowed we characterize the class of mechanisms that are strategy proof ex post individually rational ex post budget balanced and collusion proof in these mechanisms the price of each object is fixed in advance and the objects are reallocated according to the unique core assignment of the shapley scarf economy associated with the prices the special case in which all prices are zero is the core mechanism studied by shapley and scarf our mechanisms are compelling alternatives to the groves mechanisms which satisfy neither budget balance nor our condition of collusion proofness journal of economic literature classification numbers c71 c78 d71 d78 d89

house allocation with existing tenants an equivalence abstract we analyze two mechanisms designed to eliminate inefficiencies in house allocation problems where there are both existing tenants and newcomers the first mechanism chooses the unique core allocation of a sister exchange economy constructed by endowing each existing tenant with her current house and each newcomer with a random vacant house the second mechanism chooses an ordering from a given distribution and determines the final outcome as follows assign the agents the best available house one at a time following their ordering in the queue and whenever an agent demands the house of an existing tenant who is still in the line modify the queue by inserting the existing tenant at the top whenever a loop of existing tenants forms assign each of them the house she demands and proceed we show that the first mechanism is equivalent to an extreme case of the second which favors the newcomers

determinants of sovereign yield spreads in the eurozone a bayesian approach abstract we analyze the determinants of sovereign yields spreads of emu member states applying bayesian model averaging bma to annual panel data from 1999 to 2009 bma is well suited in cases of small samples and high model uncertainty this seems to be the case in modeling sovereign yield spreads in the eurozone since the literature reports heterogeneous results with respect to significant explanatory variables we are testing a number of variables reported to be significant in the literature and find that the most likely country specific drivers of yield spreads are fiscal variables such as budget balance and government debt as well as external sector variables such as terms of trade trade balance and openness global financing conditions indicated by the us interest rate and market sentiments indicated by corporate bond spreads are likely to influence sovereign yield spreads

sovereign default exit and contagion in a monetary union abstract the european sovereign debt crisis is characterized by the simultaneous surge in borrowing costs in the gips countries after 2008 we present a theory which can account for the behavior of sovereign bond spreads in southern europe between 1998 and 2012 our key theoretical argument is related to the bail out guarantee provided by a monetary union which endogenously varies with the number of member countries in sovereign debt trouble we incorporate this theoretical foundation in an otherwise standard small open economy dsge model and explain i the convergence of interest rates on sovereign bonds following the european monetary integration in late 1990s and ii following the heightened default risk of greece the sudden surge in interest rates in countries with relatively sound economic and financial fundamentals we calibrate the model to match the behavior of the portuguese economy over the period of 1998 to 2012

strategyproof assignment by hierarchical exchange we give a characterization of the set of group strategyproof pareto optimal and reallocation proof allocation rules for the assignment problem where individuals are assigned at most one indivisible object without any medium of exchange although there are no property rights in the model the rules satisfying the above criteria imitate a trading procedure with individual endowments in which individuals exchange objects from their hierarchically determined endowment sets in an iterative manner in particular these assignment rules generalize gale s top trading cycle procedure the classical rule for the model in which each individual owns an indivisible good

individual versus group strategy proofness when do they coincide a social choice function is group strategy proof on a domain if no group of agents can manipulate its final outcome to their own benefit by declaring false preferences on that domain there are a number of economically significant domains where interesting rules satisfying individual strategy proofness can be defined and for some of them all these rules turn out to also satisfy the stronger requirement of group strategy proofness we provide conditions on domains guaranteeing that for all rules defined on them individual and group strategy proofness become equivalent we also provide a partial answer regarding the necessity of our conditions

yield spreads on emu government bonds government bond spreads we provide evidence that the movements in yield differentials between euro zone government bonds explained by changes in international risk factors as measured by banking and corporate risk premiums in the united states are more pronounced for bonds issued by italy and spain liquidity factors play a smaller role so policies meant to increase financial market efficiency do not appear sufficient to deliver a seamless bond market in the euro area the risk of default is a small but important component of yield differentials movements which signal market perceptions of fiscal vulnerability impose market discipline on national fiscal policies and may be reduced only by further convergence in debt ratios lorenzo codogno carlo favero and alessandro missale

group incentive compatibility for matching with contracts abstract hatfield and milgrom hatfield john william milgrom paul r 2005 matching with contracts amer econ rev 95 913 935 present a unified model of matching with contracts which includes the standard two sided matching and some package auction models as special cases they show that the doctor optimal stable mechanism is strategy proof for doctors if hospitals preferences satisfy substitutes and the law of aggregate demand we show that the doctor optimal stable mechanism is group strategy proof for doctors under these same conditions that is no group of doctors can make each of its members strictly better off by jointly misreporting their preferences we derive as a corollary of this result that no individually rational allocation is preferred by all the doctors to the doctor optimal stable allocation

a unified approach to investigate pure and wake up call contagion evidence from the eurozone s first financial crisis abstract this paper simultaneously analyzes wake up call and pure contagion of sovereign risk in the eurozone during its recent financial crisis pure contagion of sovereign risk means the transmission of negative effects after a shock to a country which are not reflected in the risk pricing of fundamental determinants of sovereign risk of the recipient country wake up call contagion is defined as the change of sovereign risk pricing by market participants after negative events in a single country or a group of countries to examine both types of contagion in a unified framework we apply an extension of the canonical model for contagion proposed by pesaran and pick 2007 and metiu 2012 in that we allow for time varying coefficients controlling for changes in the risk pricing by investors we detect several channels of pure contagion between 2008 and 2012 but with decreasing number over time further we find evidence for a disruption of sovereign risk contagion channels from greece ireland and portugal to spain italy france and belgium after their respective bailouts as was desired by policymakers for all eurozone countries considered we observe an increase in the relevance of general risk aversion towards sovereign debt since may 2010 our model extension yields a device that is suitable to determine whether policy interventions are required and to judge their success ex post

capital shortfall a new approach to ranking and regulating systemic risks the financial crisis of 2007 2009 has given way to the sovereign debt crisis of 2010 2012 yet many of the banking issues remain the same we discuss a method to estimate the capital that a financial firm would need to raise if we have another financial crisis this measure of capital shortfall is based on publicly available information but is conceptually similar to the stress tests conducted by us and european regulators we argue that this measure summarizes the major characteristics of systemic risk and provides a reliable interpretation of the past and current financial crises

dynamic kidney exchange we study how barter exchanges should be conducted through a centralized mechanism in a dynamically evolving agent pool with time and compatibility based preferences we derive the dynamically efficient two way and multi way exchange mechanisms that maximize total discounted exchange surplus recently several live donor kidney exchange programs were established to swap incompatible donors of end stage kidney disease patients since kidney exchange can be modeled as a special instance of our more general model dynamically efficient kidney exchange mechanisms are derived as corollaries we make policy recommendations using simulations

why do popular mechanisms lack efficiency in random environments we consider the problem of randomly assigning n indivisible objects to n agents recent research introduced a promising mechanism the probabilistic serial that has superior e ciency properties than the most common real life mechanism random priority on the other hand mechanisms based on gale s celebrated top trading cycles method have long dominated the indivisible goods literature with the exception of the present context thanks to their outstanding e ciency features we present an equivalence

an econometric model of cattle inventories dynamic regression equations are estimated for each beef cattle breeding herd and beef cattle inventories at two levels of aggregation the u s and montana the analysis for montana was utilized as a guide for specification of the national equation to reduce the inference problem associated with letting the sample data help specify the model rational lags on average price received by farmers for calves and the ratio of fed beef to corn prices at omaha constitute the primary explanatory variables the equations perform exceedingly well over the sample period 1950 80 and in post sample forecasts with the sample truncated back to 1970

how does liquidity affect government bond yields the paper explores the determinants of yield differentials between sovereign bonds using euro area data there is a common trend in yield differentials which is correlated with a measure of aggregate risk in contrast liquidity differentials display sizeable heterogeneity and no common factor we propose a simple model with endogenous liquidity demand where a bond s liquidity premium depends both on its transaction cost and on investment opportunities the model predicts that yield differentials should increase in both liquidity and risk with an interaction term of the opposite sign testing these predictions on daily data we find that the aggregate risk factor is consistently priced liquidity differentials are priced for a subset of countries and their interaction with the risk factor is in line with the model s prediction and crucial to detect their effect

the probabilistic serial mechanism with private endowments abstract a random assignment is ordinally efficient if it is not stochastically dominated with respect to individual preferences over sure objects when there are no private endowments the set of ordinally efficient random assignments is characterized by the eating algorithm bogomolnaia and moulin 2001 when there are private endowments the main requirement is individual rationality however the eating algorithm fails to deliver this property our contribution is the natural generalization of the eating algorithm for this general class of problems the family of this generalized eating algorithm characterizes the set of individually rational and ordinally efficient random assignments a special solution in this family the individually rational probabilistic serial ps ir also achieves a new fairness axiom no justified envy however it is not immune to strategic manipulation we show that individual rationality no justified envy and strategy proofness are incompatible

group strategyproof cost sharing the role of indifferences every agent reports his willingness to pay for one unit of a good a mechanism allocates goods and cost shares to some agents we characterize the group strategyproof gsp mechanisms under two alternative continuity conditions interpreted as tie breaking rules with the maximalist rule max an indifferent agent is always served with the minimalist rule min an indifferent agent does not get a unit of the good gsp and max characterize the cross monotonic mechanisms these mechanisms are appropriate whenever symmetry is required on the other hand gsp and min characterize the sequential mechanisms these mechanisms are appropriate whenever there is scarcity of the good our results are independent of an underlying cost function they unify and strengthen earlier results for particular classes of cost functions

was it different the second time an empirical analysis of contagion during the crises in greece 2009 15 over the period between end 2009 and end 2015 greece experienced two discernible financial crises this article undertakes a correlation analysis of risk premia to investigate the nature and extent of contagion from these crises to other selected euro zone countries a commonly expressed view is that the effects of the second crisis were more muted since the systemic risks were seen by markets as being lower however using a rolling correlation model a dcc garch model and a t copula model we find that this is not the case broadly speaking the contagion effects of the second crisis were at least as large as those associated with the first one

group strategy proofness in private good economies many salient rules to allocate private goods are not only strategyproof but also group strategy proof in appropriate domains of definition hence diminishing the traditional conflict between incentives and efficiency that is so for solutions to matching division cost sharing house allocation and auctions in spite of the substantive disparity between these cases in a general framework encompassing all of them we prove that the equivalence between the two forms of strategy proofness is due to an underlying common structure that transcends the many differences between the contexts and the mechanisms for which it holds jel c78 d44 d63 d71 d82

exchange in a general market with indivisible goods abstract we show how to restrict trades in exchange markets with heterogeneous indivisible goods so that the resulting restricted exchange markets the fixed deal exchange markets have a unique core allocation our results on fixed deal exchange markets generalize classical results on the shapley scarf housing market in which each agent owns one good only furthermore we define the class of fixed deal exchange rules for general exchange markets and prove that these are the only exchange rules that satisfy strategyproofness individual rationality and a weak form of efficiency

coalitional strategy proof house allocation abstract we consider house allocation without endowments we show that there is a unique maximal domain including all strict preferences on which efficiency and coalitional strategy proofness are compatible a preference relation belongs to the unique maximal domain if it is a strict descending ranking of houses to a certain house and indifference holds over it and the remaining houses we also show that on this domain mixed dictator pairwise exchange rules are the only rules satisfying efficiency and coalitional strategy proofness journal of economic literature classification numbers c78 d63 d71

on the operation of multiple matching markets abstract we provide a new perspective on how to operate matching markets when there are many types of markets our finding is that the market wise adaptation of strategy proof and non wasteful rules yields a strategy proof rule with the following efficiency property no strategy proof rule pareto dominates the rule such rules are abundant as they include the market wise use of the well known priority based rules of the top trading cycles and the deferred acceptance this result gives theoretical support to the independent operation of markets observed in real life markets as well as our practice in market design that separately treats each market for its design

strategy proof stochastic assignment abstract i study strategy proof assignment mechanisms where the agents reveal their preference rankings over the available objects a stochastic mechanism returns lotteries over deterministic assignments and mechanisms are compared according to first order stochastic dominance i show that non wasteful strategy proof mechanisms are not dominated by strategy proof mechanisms however non wastefulness is highly restrictive when the mechanism involves randomization in fact the random priority mechanism i e the random serial dictatorship and a recently adopted school choice mechanism deferred acceptance with random tie breaking are wasteful i find that both these mechanisms are dominated by strategy proof mechanisms in general strategy proof improvement cannot be due to merely reshuffling objects and therefore must involve assigning more objects

sovereign bond yield spreads a time varying coefficient approach abstract we study the determinants of sovereign bond yield spreads across 10 emu countries between q1 1999 and q1 2010 we apply a semiparametric time varying coefficient model to identify to what extent an observed change in the yield spread is due to a shift in macroeconomic fundamentals or due to altering risk pricing we find that at the beginning of emu the government debt level and the general investors risk aversion had a significant impact on interest differentials in the subsequent years however financial markets paid less attention to the fiscal position of a country and the safe haven status of germany diminished in importance by the end of 2006 two years before the fall of lehman brothers financial markets began to grant germany safe haven status again one year later when financial turmoil began the market reaction to fiscal loosening increased considerably the altering in risk pricing over time period confirms the need of time varying coefficient models in this context

affine modeling of credit risk pricing of credit events and contagion we propose a discrete time affine pricing model that simultaneously allows for i the presence of systemic entities by departing from the no jump condition on the factors conditional distribution

strategy proofness and pivotal voters a direct proof of the gibbard satterthwaite theorem this paper presents a proof of the gibbard satterthwaite theorem the importance of the theorem itself has been widely recognized and there already exist several alternative proofs the present one is offered because it is technically simple direct and emphasizes the role of pivotal individuals in the manipulation of voting schemes some indirect proofs of the theorem rely on the connections between voting schemes and social welfare functions and one interesting corollary of such proofs is to provide new arguments in behalf of arrow s condition of independence of irrelevant alternatives yet a direct proof has the advantage of showing the complete independence of the manipulation phenomena from any requirement of consistency in choice under varying sets of alternatives also our proof emphasizes the role of pivotal individuals in manipulation a classical approach in social choice theory is to concentrate on the global distribution of power among groups of agenits i e on the ability of coalitions to impose outcomes regardless of the preferences of agents not in the coalition for example standard proofs of arrow s theorem concentrate on decisive coalitions to end up proving that there must exist one such coalition containing a single individual the dictator our approach concentrates on the local distribution of power among single agents i e on the ability of each single individual to determine the social outcome given the preferences of all other members of society this approach may be more intuitive for some readers moreover it closely parallels the work on incentives in economic environments with public goods and suggests a possible way to unify results which have been obtained from different initial specifications we do not attempt such a rejoinder here but let us observe the following for certain environments with public goods where transfer payments make perfect sense nontrivial strategy proof mechanisms can be obtained by appropriately taxing pivotal agents so that they take into account the costs that their actions impose upon others 2 one explanation for the nonexistence of equivalent mechanisms in our case is that the environment as specified does not allow for a corresponding procedure whereby different costs to individuals could be attached to different acts of preference revelation

international comparisons of cattle cycles the time series properties of cattle production in three countries with different technologies argentina the united states and uruguay are studied in order to shed light on the role of technology in the dynamics of the cattle sector four series are analyzed for each country slaughter price stock of cows and total herd spectral decomposition of the time series shows the existence of cycles having surprising regularity for all the four time series the three countries exhibit very similar cyclicities in spite of their different technologies and economic environment

random matching under dichotomous preferences we consider bilateral matching problems where each person views those on the other side of the market as either acceptable or unacceptable an acceptable mate is preferred to remaining single and the latter to an unacceptable mate all acceptable mates are welfare wise identical using randomization many efficient and fair matching methods define strategyproof revelation mechanisms randomly selecting a priority ordering of the participants is a simple example equalizing as much as possible the probability of getting an acceptable mate across all participants stands out for its normative and incentives properties the profile of probabilities is lorenz dominant and the revelation mechanism is group strategyproof for each side of the market our results apply to the random assignment problem as well

top trading with fixed tie breaking in markets with indivisible goods abstract we study markets with indivisible goods where monetary compensations are not possible each individual is endowed with an object and a preference relation over all objects when preferences are strict gale s top trading cycles algorithm finds the unique core allocation when preferences are not necessarily strict we use an exogenous profile of tie breakers to resolve any ties in individuals preferences and apply gale s top trading cycles algorithm for the resulting profile of strict preferences we provide a foundation of these simple extensions of gale s top trading cycles algorithm from strict preferences to weak preferences we show that gale s top trading cycles algorithm with fixed tie breaking is characterized by individual rationality strategy proofness weak efficiency non bossiness and consistency our result supports the common practice in applications to break ties in weak preferences using some fixed exogenous criteria and then to use a good and simple rule for the resulting strict preferences

eurozone sovereign contagion evidence from the cds market 2005 2010 abstract this paper analyses the dynamics of the credit default swap cds market of piigs france germany and the uk for the period of 2005 2010 the study is performed on the basis of the datastream and dtcc data on cds spreads and the bis data on cross border exposures the analysis of the data shows that sovereign risk mainly concentrates in the eu countries the ewma correlation analysis and the granger causality test demonstrate that there was contagion effect since correlations and cross county interdependencies increased already after august 2007 furthermore the irf analysis shows that among piigs the cds markets of spain and ireland have the biggest impact on the european cds market whereas the cds market of the uk does not cause a big distress in the eurozone the adjusted correlation analysis confirms that greece and other piigs even spain and italy have lower capacity to trigger contagion than core eu countries besides portugal is the most vulnerable country in the sample whereas the uk is the most immune to shocks

reclaim proof allocation of indivisible objects abstract we study desirability axioms imposed on allocations in indivisible object allocation problems the existing axioms in the literature are various conditions of robustness to blocking coalitions with respect to agents ex ante individual rationality and group rationality and ex post pareto efficiency endowments we introduce a stringent axiom that encompasses and strengthens the existing ones an allocation is reclaim proof if it is robust to blocking coalitions with respect to any conceivable interim endowments of agents this is an appealing property in dynamic settings where the assignments prescribed by an allocation to be implemented need to be made in multiple rounds rather than all in one shot we show that an allocation is reclaim proof if and only if it is induced by a yrmh igyt mechanism introduced by abdulkadiroglu and sonmez 1999 and if and only if it is a competitive allocation

gauging potential sovereign risk contagion in europe abstract this study adopts the covar methodology to analyse the tail risk relationships among european sovereigns which provide arguably important information for policymakers to identify countries that should come under close scrutiny during the current debt crisis

risk assessment on euro area government bond markets the role of governance abstract since the announcement of the outright monetary transactions program omt government bond yield spreads have decreased substantially but have not fallen to pre crisis levels this paper argues that the debt to gdp ratio has become less relevant as a determinant for government bond spreads while financial markets have become more concerned about the willingness and the capability to cooperate with the institutions that conduct the adjustment programs since the announcement of omt the paper links the willingness and the capability to cooperate to political stability and the quality of governance for which the indicators are available from the world bank by means of a time varying coefficient approach it can be shown that the coefficient for a composite world bank indicator on the quality of governance has outpaced other possible determinants of government bond spreads since the announcement of omt

incentive compatibility in a market with indivisible goods abstract in a market in which each trader s initial endowment is one unit of an indivisible good there exists an incentive compatible procedure for reaching a competitive allocation this contrasts with some recent results for similar problems

strategy proofness and the core in house allocation problems abstract we study house allocation problems introduced by l shapley and h scarf 1974 j math econ 1 23 28 we prove that a mechanism a social choice function is individually rational anonymous strategy proof and nonbossy but not necessarily pareto efficient if and only if it is either the core mechanism or the no trade mechanism where the no trade mechanism is the one that selects the initial allocation for each profile of preferences this result confirms the intuition that even if we are willing to accept inefficiency there exists no interesting strategy proof mechanism other than the core mechanism journal of economic literature classification numbers c71 c78 d71 d78 d89