convergence to efficiency in a simple market with incomplete information a model of trade with m buyers and m sellers is considered in which price is set to equate revealed demand and supply in a bayesian nash equilibrium each trader acts not as a price taker but instead misrepresents his true demand supply to influence price in his favor this causes inefficiency we show that in any equilibrium the amount by which a trader misreports is o 1 m and the corresponding inefficiency is o 1 m2 the indeterminacy and the inefficiency that is caused by the traders bargaining behavior in small markets thus rapidly vanishes as the market increases in size

a brain gain with a brain drain abstract we study human capital depletion and formation in an economy open to out migration as opposed to an economy which is closed under the assumption of asymmetric information the enlarged opportunities and the associated different structure of incentives can give rise to a brain gain in conjunction with a brain drain migration by high skill members of its workforce notwithstanding the home country can end up with a higher average level of human capital per worker

approximately competitive equilibria in large finite economies abstract we consider exchange economies where each consumer may report or act according to any demand function provided that there exist situations that the consumer finds plausible in which the reported demand performs at least as well as the true demand we identify conditions under which as the size of the economy increases all the market clearing prices and allocations of the reported economy approximate the competitive equilibria of the true economy journal of economic literature classification numbers d51 d82

human capital depletion human capital formation and migration a blessing or a curse abstract we specify conditions under which a strictly positive probability of employment in a foreign country raises the level of human capital formed by optimizing workers in the home country while some workers migrate taking along more human capital than if they had migrated without factoring in the possibility of migration a form of brain drain other workers stay at home with more human capital than they would have formed in the absence of the possibility of migration a form of brain gain

incentive compatibility and competitive allocations abstract it is shown that as the number of individuals in an economy grows the demand functions which are optimal for an agent converge to the competitive price taking demand

age and great invention great achievements in knowledge are produced by older innovators today than they were a century ago using data on nobel prize winners and great inventors i find that the age at which noted innovations are produced has increased by approximately 6 years over the 20th century this trend is consistent with a shift in the life cycle productivity of great minds it is also consistent with an aging workforce the paper employs a semi parametric maximum likelihood model to 1 test between these competing explanations and 2 locate any specifi cs hifts in life cycle productivity the productivity explanation receives considerable support i find that innovators are much less productive at younger ages beginning to produce major ideas 8 years later at the end of the 20th century than they did at the beginning furthermore the later start to the career is not compensated for by increasing productivity beyond early middle age i show that these distinct shifts for knowledge based careers are consistent with a knowledgebased theory where the accumulation of knowledge across generations leads innovators to seek more education over time more generally the results show that individual innovators are productive over a narrowing span of their life cycle a trend that reduces other things equal the aggregate output of innovators this drop in productivity is particularly acute if innovators raw ability is greatest when young

brain drain and economic growth theory and evidence we focus on the impact of migration prospects on human capital formation and growth in a small open developing economy we assume that agents are heterogeneous in skills and take their educational decisions in a context of uncertainty regarding future migrations we distinguish two growth effects an ex ante brain effect migration prospects foster investments in education because of higher returns abroad and an ex post drain effect because of actual migration flows the case for a beneficial brain drain bbd emerges when the first effect dominates i e when the average level of human capital is higher in the economy opened to migrations than in the closed economy we derive the theoretical conditions required for such a possibility to be observed using cross section data for 37 developing countries we find that the possibility of a bbd could be more than a theoretical curiosity

long memory and nonlinear mean reversion in japanese yen based real exchange rates abstract the extraordinary difficulty in uncovering parity reversion in yen based real exchange rates has often been ascribed to a missing trend variable this study identifies an alternative explanation and shows that the puzzling behavior of real yen rates may stem from long memory dynamics which undermine unit root tests in their ability to detect mean reversion the long memory findings are consistent with the long swings in yen exchange rates during the current float further analysis also reveals evidence of non monotonic reversion toward parity

the robustness of equilibria to incomplete information a number of papers have shown that a strict nash equilibrium action profile of a game may never be played if there is a small amount of incomplete information see for example carlsson and van damme 1993a we present a general approach to analyzing the robustness of equilibria to a small amount of incomplete information a nash equilibrium of a complete information game is said to be robust to incomplete information if every incomplete information game with payoffs almost always given by the complete information game has an equilibrium which generates behavior close to the nash equilibrium we show that many games with strict equilibria have no robust equilibrium and examine why we get such different results from existing refinements if a game has a unique correlated equilibrium it is robust a natural many player many action generalization of risk dominance is a sufficient condition for robustness

bidding for brains intellectual property rights and the international migration of knowledge workers we introduce international mobility of knowledge workers into a model of nash equilibrium ipr policy choice among countries we show that governments have incentives to use iprs in a bidding war for global talent resulting in nash equilibrium iprs that can be too high rather than too low from a global welfare perspective these incentives become stronger as developing countries grow in size and wealth thus allowing them to prevent the poaching of their brains by larger wealthier markets

asymptotic efficiency in large exchange economies with asymmetric information the authors provide conditions on an exchange economy with asymmetric information that guarantee that when the economy is replicated sufficiently often there will be an allocation that is incentive compatible individually rational and nearly efficient the main theorem covers both the case in which aggregate uncertainty remains when the economy is replicated and the case in which replication eliminates aggregate uncertainty in addition the authors demonstrate how their theorem does or does not apply to standard asymmetric information problems such as the buyer s bid double auction problem akerlof s lemons problem and insurance with asymmetric information copyright 1992 by the econometric society

can a brain drain be good for growth in the source economy this paper analyzes the interaction between income distribution human capital accumulation and migration it shows that when migration is not a certainty a brain drain may increase average productivity and equality in the source economy even though average productivity is a positive function of past average levels of human capital in an economy it is also shown how the temporary possibility of emigration may permanently increase the average level of productivity of an economy

dynamics of persistence in international inflation rates characteristics of inflation play a key role in policy formulation and market analysis several studies have analyzed inflation persistence and reached diverging conclusions in this paper we investigate the dynamics of inflation persistence using fractionally integrated processes and find that there has been a clear decline in inflation persistence in the united states over the past two decades we also show that the presence of fractional integration in inflation successfully explains previous diverging results lastly we provide some international comparisons to examine the extent to which there has been a commensurate decline in inflation persistence in the other g7 economies

immigrant selection in the oecd in this paper we examine the determinants of educational selectivity in immigration using immigrant stock data for 70 source countries and 21 oecd destination countries as observed in the year 2000 2001 we develop a variant of the roy model to estimate the determinants of educational selectivity two key findings emerge first the effect of the skill premium which is at the core of the roy model can be observed only after we take into account the poverty constraints operating in the source countries second cultural similarities colonial legacies and physical distance are often more important determinants of educational selectivity than wage incentives or selective immigration policy

on the persistence of the eonia spread abstract the european overnight rate eonia signals the monetary policy stance of the european central bank controllability of the eonia requires that the persistence of the spread between the eonia and the key policy rate remains sufficiently low we apply fractional integration techniques to examine its changing persistence

interest rate corridors and reserves abstract this paper evaluates reserves regimes versus interest rate corridors which have become competing frameworks for monetary policy implementation rate corridors relying on lending and deposit facilities to create ceilings and floors for overnight interest rates evince mixed results on controlling volatility reserve requirements allow period average smoothing of interest rates but even if remunerated are subject to reserve avoidance activities a system of voluntary period average reserve commitments could offer equivalent rate smoothing advantages if central banks created symmetric opportunity costs of meeting or falling short of period average reserve requirements or commitments they could achieve flat reserve demand on settlement day

global talent flows the global distribution of talent is highly skewed and the resources available to countries to develop and utilize their best and brightest vary substantially the migration of skilled workers across countries tilts the deck even further using newly available data the paper first reviews the landscape of global talent mobility which is both asymmetric and rising in importance next the determinants of global talent flows at the individual and firm levels are presented and some important implications are sketched third the national gatekeepers for skilled migration and broad differences in approaches used to select migrants for admission are reviewed looking forward the capacity of people firms and countries to successfully navigate this tangled web of global talent will be critical to their success

perfect competition in asymmetric information economies compatibility of efficiency and incentives the idea of perfect competition for an economy with asymmetric information is formalized via an idiosyncratic signal process in which the private signals of almost every individual agent can influence only a negligible group of agents and the individual agents relevant signals are essentially pairwise independent conditioned on the true states of nature thus there is no incentive for an individual agent to manipulate her private information the existence of incentive compatible ex post walrasian allocations is shown for such a perfectly competitive asymmetric information economy with or without common values consequently the conflict between incentive compatibility and pareto eciency is resolved exactly and its asymptotic version is derived for a sequence of large but finite private information economies

income maximization and the selection and sorting of international migrants abstract two prominent features of international labor movements are that the more educated are more likely to emigrate positive selection and more educated migrants are more likely to settle in destination countries with high rewards to skill positive sorting using data on emigrant stocks by schooling level and source country in oecd destinations we find that a simple model of income maximization can account for both phenomena results on selection show that migrants for a source destination pair are more educated relative to non migrants the larger is the absolute skill related difference in earnings between the destination country and the source results on sorting indicate that the relative stock of more educated migrants in a destination is increasing in the absolute earnings difference between high and low skilled workers we use our framework to compare alternative specifications of international migration estimate the magnitude of migration costs by source destination pair and assess the contribution of wage differences to how migrants sort themselves across destination countries

limit properties of equilibrium allocations of walrasian strategic games abstract we characterize the set of equilibrium allocations of walrasian strategic games where each agent manipulates his strategic demand map to his benefit we first show that for a finite economy the set of cournot nash equilibrium allocations will be large and the equilibrium allocation map will not in general possess a closed graph property then we show that with appropriate smoothness conditions and the regularity condition on the mean aggregate limit excess demand map true walrasian allocations in a large economy can be claimed to be sufficiently robust against strategic manipulations of agents demand maps

self selection and the earnings of immigrants this paper analyzes the way in which the earnings of the immigrant population may be expected to differ from the earnings of the native population because of the endogeneity of the decision to migrate the empirical study shows that differences in the u s earnings of immigrants with the same measured skills but from different home countries are attributable to variations in political and economic conditions in the countries of origin at the time of migration excerpt

equilibria and incentives in private information economies abstract this paper considers three solution concepts in a large private information economy namely walrasian expectations equilibrium private core and insurance equilibrium it shows that these three concepts coincide with each other when the agents are informationally negligible in such an economy in contrast to the finite agent setting one can construct a large private information economy in which incentive compatibility fails completely in the sense that almost every agent in any walrasian expectations equilibrium private core insurance equilibrium allocation has the incentive to misreport her type

developing science scientific performance and brain drains in the developing world abstract establishing a strong scientific community is important as countries develop and requires both producing and retaining of important scientists we show that developing countries produce a sizeable number of important scientists but that they experience a tremendous brain drain education levels population and per capita gdp are positively related to the number of important scientists born in and staying in a country our analysis indicates that democracy and urbanization are associated with the production of more important scientists although democracy is associated with more out migration

monetary policy implementation and overnight rate persistence overnight money market rates are the predominant operational target of monetary policy as a consequence central banks have redesigned the implementation of monetary policy to keep the deviations of the overnight rate from the key policy rate small and short lived this paper uses fractional integration techniques to explore how the operational framework of four major central banks afiects the persistence of overnight rates our results suggest that a well communicated and transparent interest rate target of the central bank is a particularly important condition for a low degree of overnight rate persistence

informational size and incentive compatibility we examine a general equilibrium model with asymmetrically informed agents the presence of asymmetric information generally presents a conflict between incentive com patibility and pareto efficiency we present a notion of informational size and show that the conflict between incentive compatibility and efficiency can be made arbitrarily small if agents are of sufficiently small informational size the incompatibility of pareto efficiency and incentive compatibility is a central theme in economics and game theory the issues associated with this incompatibility are particularly important in the design of resource allocation mechanisms in the presence of asymmetrically informed agents where the need to acquire information from agents in order to compute efficient outcomes and the incentives agents have to misrepresent that information for personal gain come into conflict despite a large literature that focuses on these issues there has been little work aimed at understanding those situations in which informational asymmetries are quantitatively important virtually every transaction is characterized by some asymmetry of information any investor who buys or sells a share of stock generally knows something rel evant to the value of the share that is not known to the person on the other side of the transaction in order to focus on more salient aspects of the problem many models rightly ignore the incentive problems associated with informa tional asymmetries in the belief that for the problem at hand agents are infor mationally small however few researchers have investigated the circumstances under which an analysis that ignores these incentive problems will yield results similar to those obtained when these problems are fully accounted for in this paper we study a class of mechanism design problems our goal is to formalize informational size in a way that when agents are informationally small 1 early versions of this paper circulated under the titles informational smallness and pareto effi ciency and informational smallness and incentive compatibility we thank jacques cremer dean foster andreu mas colell stephen morris david schmeidler and particularly faruk gul for help ful conversations and rajiv vohra for a very careful reading we also thank the numerous partici pants in seminars at which this paper was presented for helpful comments we also thank an editor and the referees for very helpful comments and thank ichiro obara for pointing out an error in an earlier version postlewaite gratefully acknowledges support from the national science foundation

informational robustness of competitive equilibria abstract consider an exchange economy with complete information we perturb this economy by assuming that each agent s observation about the true state of the world is noisy the paper investigates the robustness of equilibria of the complete information economy with respect to incomplete information we provide conditions under which complete information equilibria are limits of equilibria of the economies with incomplete information as the noise in the signal converges to zero journal of economic literature classification numbers d51 d82