money and prices under uncertainty we study whether monetary economies display nominal indeterminacy equivalently whether monetary policy determines the path of prices under uncertainty in a simple stochastic cash in advance economy we find that indeterminacy arises and is characterized by the initial price level and a probability measure associated with state contingent nominal bonds equivalently monetary policy determines an average but not the distribution of inflation across realizations of uncertainty the result does not derive from the stability of the deterministic steady state and is not affected essentially by price stickiness nominal indeterminacy may affect real allocations in cases we identify our characterization applies to stochastic monetary models in general and it permits a unified treatment of the determinants of paths of inflation copyright 2005 wiley blackwell

extrinsic uncertainty and the informational role of prices abstract we study a financial economy with finitely many states of private information there are two agents informed and uninformed we define agents expectations on future equilibrium prices as a probability distribution over k distinct values i e we introduce k extrinsic events we show that there are open sets of economies with nonrevealing and also with partially revealing equilibria for an appropriate choice of self fulfilling price expectations observable equilibrium prices are signal invariant journal of economic literature classification numbers d52 d82 d84

the relation between tax rates and pre tax returns direct evidence from the 1981 and 1986 tax rate reductions abstract this study documents one effect of the theory of implicit taxes providing evidence that a change in the tax rate results in a change in pre tax returns yield spreads of pairs of treasury bills maturing in the last week of december and the first week of january are examined year ends not affected by rate changes show a significant positive yield spread between these pairs of bills reflecting an upward sloping yield curve however for year ends coinciding with the tax rate reductions of 1981 and 1986 there is a significant negative yield spread between these pairs of bills

the economic impact of social ties evidence from german reunification we use the fall of the berlin wall in 1989 to show that personal relationships which individuals maintain for noneconomic reasons can be an important determinant of regional economic growth we show that west german households who had social ties to east germany in 1989 experienced a persistent rise in their personal incomes after the fall of the berlin wall moreover the presence of these households significantly affects economic performance at the regional level it increases the returns to entrepreneurial activity the share of households who become entrepreneurs and the likelihood that firms based within a given west german region invest in east germany as a result west german regions that for idiosyncratic reasons have a high concentration of households with social ties to the east exhibit substantially higher growth in income per capita in the early 1990s a one standard deviation rise in the share of households with social ties to east germany in 1989 is associated with a 4 7 percentage point rise in income per capita over six years we interpret our findings as evidence of a causal link between social ties and regional economic

precautionary savings and self selection evidence from the german reunification experiment in the absence of complete insurance expected future income shocks lead prudent individuals to build up precautionary savings in order to avoid wide fluctuations in the consumption path the reaction of savings to expected future shocks is stronger the more risk averse an individual is risk aversion might influence not only the savings behavior of an individual facing a stochastic income path but it can also affect occupational choice in the first place in particular risk averse individuals might choose occupations that are associated with less risky income paths while less risk averse individuals might prefer occupations with higher income risk assessing the importance of self selection of individuals into occupations according to their risk aversion is difficult since risk aversion is usually unobserved yet failing to control for unobserved risk aversion in regressions of wealth on measures of labor income risk will lead to a bias if selfselection takes place since measures of labor income risk will be negatively correlated with the error term that is capturing the unobserved risk aversion this could lead to a rejection of the theory of precautionary savings even if individuals act according to the theory

group lending repayment incentives and social collateral abstract in this paper we investigate the impact on repayment rates of lending to groups which are made jointly liable for repayment this type of scheme especially in the guise of the grameen bank in bangladesh has received increasing attention we set up and analyze the repayment game which group lending gives rise to our analysis suggests that such schemes have both positive and negative effects on repayment rates the positive effect is that successful group members may have an incentive to repay the loans of group members whose projects have yielded insufficient return to make repayment worthwhile the negative effect arises when the whole group defaults even when some members would have repaid under individual lending we also show how group lending may harness social collateral which serves to mitigate its negative effect

learning about a new technology pineapple in ghana this paper investigates the role of social learning in the diffusion of a new agri cultural technology in ghana we use unique data on farmers communication patterns to define each individual s information neighborhood conditional on many potentially confounding variables we find evidence that farmers adjust their inputs to align with those of their information neighbors who were surpris ingly successful in previous periods the relationship of these input adjustments to experience further indicates the presence of social learning in addition applying the same method to input choices for another crop of known technol ogy correctly indicates an absence of social learning effects jel d83 013 033 q16

immigration and structural change evidence from post war germany does immigration accelerate sectoral change towards high productivity sectors this paper uses the mass displacement of ethnic germans from eastern europe to west germany after world war ii as a natural experiment to study this question a simple two sector model of the economy in which moving costs prevent the marginal product of labor to be equalized across sectors predicts that immigration boosts output per worker by expanding the high productivity sector but decreases output per worker within a sector using german district level data from before and after the war we find strong empirical support for these predictions

competitive equilibrium with unawareness in economies with production abstract this paper investigates an extension of the gei unawareness framework by modica et al econ theory 12 1998 259 to economies with entrepreneurial production existence of equilibrium is guaranteed given decreasing returns to scale firm s value and investment decision in equilibrium are characterized an example of commodity innovation shows that the effect of different degrees of awareness on investment decisions depend upon the degree of risk aversion in the case of log preferences unawareness may not matter for commodity innovation although this depends on other preference features

depressing dependence transfers and economic growth in the german states 1975 2005 abstractdepressing dependence transfers and economic growth in the german states 1975 2005 regional studies most countries pay substantial intergovernmental transfers to poor regions with the aim of achieving regional convergence consequently transfers should have a positive effect on economic growth however it is equally possible that transfers perpetuate underdevelopment this paper studies empirically the effect of intergovernmental transfers on economic growth with a panel of west german states over the period 1975 2005 the findings suggest that transfers do not foster economic growth presumably because the recipients use them to subsidize declining industries

earnings regulatory capital and tax management comments abstract in the preceding papers beaver and engel and adiel investigate managerial discretion in the financial services industry this comment evaluates the contribution and limitations of both papers and suggests avenues for further extensions

children of war the long run effects of large scale physical destruction and warfare on children this paper provides causal evidence on the long term consequences of large scale physical destruction on educational attainment health status and labor market outcomes of children i exploit the plausibly exogenous region by cohort variation in the intensity of world war two wwii destruction as a unique quasi experiment i find that exposure to destruction had long lasting detrimental effects on the human capital formation health and labor market outcomes of germans who were at school age during wwii an important channel for the effect of destruction on educational attainment is the destruction of schools whereas malnutrition is partly behind the estimated impact on health

social networks and the dynamics of labour market outcomes evidence from refugees resettled in the u s recent theoretical work suggests that social networks may play an important role in the dynamics of employment and wages across groups of individuals this paper provides empirical evidence of job information flows within social networks and the non linear relationship between social network size and labor market outcomes an extended version of the model developed by calvo armengol and jackson 2004 shows that competition can exist between network members for job referrals and investigates the dynamics between the size of a social network the tenure of network members and labor market outcomes the predictions of the model are tested empirically using a unique data set of refugees resettled in the u s from 2001 2005 the empirical strategy exploits the special institutional environment of refugee resettlement i find that a one standard deviation increase in the number of network members who have arrived in the u s one year ago lowers the probability of employment by 4 9 and the average hourly wage by 70 conversely as predicted by the model more tenured network members improve labor market outcomes for recently arrived refugees

risk sharing networks and insurance against illness most risk sharing tests on developing country data are conducted at the level of the village generally the full risk sharing hypothesis is rejected this paper uses detailed data on all insurance networks within a village in tanzania networks are not clustered but largely overlapping we test whether full risk sharing occurs within these networks while village level full insurance cannot be rejected for food consumption we find evidence consistent with at least partial insurance of non food consumption via networks

stationary equilibria with incomplete markets and overlapping generations recent work on general equilibrium models with incomplete financial markets has demonstrated that when assets pay off in units of account equilibrium prices and allocations are indeterminate the equilibria in such models are also generically constrained suboptimal a central planner can typically reallocate assets in such a way as to pareto dominate the competitive equilibrium in this paper the authors consider an overlapping generations model with incomplete markets in which one asset is fiat money they show that when outside money has value in equilibrium the stationary equilibrium prices and allocations are both locally isolated and constrained optimal copyright 1992 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

staunching emigration from east germany age and the determinants of migration following the unification of germany in 1990 eastern wages and unemployment both rose rapidly i demonstrate that rising wages reduced eastern emigration greatly while rising unemployment had little effect this reflects the behavior of the young who are very sensitive to source region wages and relatively insensitive to source unemployment i show that most of the effect of source unemployment comes from the contemporaneous effect on those laid off who are more likely to be older i find that compared to stayers young emigrants are much more skilled older emigrants are slightly more skilled and commuters are not more skilled as measured by education and pre move wages my conclusions are based on a comparison of results from aggregate inter state migration data and individual data from the eastern sample of the german socio economic panel for 1990 2000 jel j61 p23

prices asset markets and indeterminacy abstract competitive equilibrium allocations are indeterminate when the net trades in commodities are constrained while the asset market is incomplete the model encompasses economies with deferred payment for commodities economies with nominal assets and economies with bundling of commodities and assets journal of economic literature classification numbers d50 d52

aggregation determinacy and informational efficiency for a class of economies with asymmetric information abstract we identify and analyze a class of economies with asymmetric information that we call quasi complete for quasi complete economies we determine equilibrium trades show that the set of fully informative equilibria is a singleton and give necessary and sufficient conditions for the existence of partially informative equilibria besides unifying some familiar settings such as those of grossman 1976 and milgrom and stokey 1982 the following new results are proved a the same restrictions that deliver gorman aggregation under symmetric information are sufficient for gorman aggregation under asymmetric information even under partially informative prices b the traditional assumptions of quadratic utilities and endowment spanning that result in the capm under symmetric information deliver a conditional capm under asymmetric information with prices that need not be fully informative c the linear equilibrium in grossman s 1976 model is the only equilibrium linear or not while minor changes in the normality assumptions result in indeterminacy and partially informative equilibria and d if there is no aggregate endowment risk asymmetrically informed agents with common priors sell the risky part of their endowment in every equilibrium journal of economic literature classification numbers d82 g14 c62

capital gains tax rates and the cost of capital for small business evidence from the ipo market abstract we examine the issue prices of small initial public offerings around the 1993 tax law change that reduced the capital gains tax on qualified small business stock we compare the actual issue price of new stock with a benchmark price that is not affected by the change in capital gains tax we find that after controlling for ipo underpricing the issue prices of qualifying small business stock after the tax rate change are significantly higher than the issue prices before the change a control sample of nonqualifying firms shows no significant difference in issue prices

equilibria with options existence and indeterminacy abstract this paper studies an economy in which trading takes place in spot commodity markets and incomplete futures markets for assets of various types there are real assets stocks or commodity futures options on real assets and a riskless nominal bond we show that for a generic set of economies parametrized by consumers endowments and structure of real assets there exists an equilibrium moreover we show that generically the set of equilibrium allocations of commodities contains a manifold of a high dimension even if the market structure is potentially complete i e the number of assets including options equals or exceeds the number of states of nature and the arrow debreu equilibrium can be achieved through sequential trading in spot and futures markets there are multiple inefficient equilibria without full rank of the asset payoff matrix

computer mediated transactions every now and then a set of technologies becomes available that sets off a period of combinatorial innovation think of standardized mechanical parts in the 1800s the gasoline engine in the early 1900s electronics in the 1920s integrated circuits in the 1970s and the internet in the last decade or so the component parts of these technologies can be combined and recombined by innovators to create new devices and applications since these innovators are working in parallel with similar components it is common to see simultaneous invention there are many well known examples such as the electric light the airplane the automobile and the telephone many scholars have described such periods of innovation using terms such as recombinant growth general purpose technologies cumulative synthesis and clusters of innovation the internet and the web are wonderful examples of combinatorial innovation in the last 15 years we have seen a huge proliferation of web applications all built from a basic set of component technologies the internet itself was a rather unlikely innovation i like to describe it as a lab experiment that got loose since the internet arose from the research community rather than the private sector it had no obvious business model other public computer networks such as aol compuserve and minitel generally used a subscription models but were centrally controlled and offered little scope for innovation at the user level the internet won out over these alternatives precisely because it offered a flexible set of component technologies which encouraged combinatorial innovation

an equilibrium analysis of information aggregation and fluctuations in markets with discrete decisions abstract this paper shows how the interaction between decentralized information gathering and discreteness of investment decisions at the individual level can generate random fluctuations in aggregate investment that involve occasionally large allocation errors this interaction is illustrated in a model in which private information is costly to acquire and prices reveal information the unique rational expectations equilibrium outcome of the model is shown to always be noisy and characterized by investment levels which may be high simply because uninformed investors are buying under the impression that the high price is a signal of good investment opportunities

good bye lenin or not the effect of communism on people s preferences preferences for redistribution as well as the generosities of welfare states differ significantly across countries in this paper we test whether there exists a feedback process of the economic regime on individual preferences we exploit the experiment of german separation and reunification to establish exogeneity of the economic system from 1945 to 1990 east germans lived under a communist regime with heavy state intervention and extensive redistribution we find that after german reunification east germans are more in favor of redistribution and state intervention than west germans even after controlling for economic incentives this effect is especially strong for older cohorts who lived under communism for a longer time period we further find that east germans preferences converge towards those of west germans we calculate that it will take one to two generations for preferences to converge completely

the determinants of cross border equity flows abstract we explore a new panel data set on bilateral gross cross border equity flows between 14 countries 1989 1996 we show that a gravity model explains international transactions in financial assets at least as well as goods trade transactions gross transaction flows depend on market size in source and destination country as well as trading costs in which both information and the transaction technology play a role distance proxies some information costs and other variables explicitly represent information transmission an information asymmetry between domestic and foreign investors and the efficiency of transactions the geography of information is the main determinant of the pattern of international transactions while there is weak support in our data for the diversification motive once we control for the informational friction we broaden the scope of our results by presenting some evidence linking the results on equity transactions to equity holdings

the eurobond market and corporate financial policy abstract on average significant positive abnormal returns are associated with eurobond issues during the period 1975 1985 the cross sectional and time series distributions of the abnormal returns are consistent with the hypothesis that impediments to the adjustment of asset supplies to new demand conditions are large enough to create profitable financing opportunities for firms our analysis demonstrates how profitable financing opportunities can persist on the eurobond market and when they are most likely to arise

the market for tax benefits evidence from leveraged esops abstract this paper examines the competitiveness of the financial markets with respect to taxes a unique set of interest rates from leveraged esops enables precise measures of the effect of a debt subsidy on prices i find that the market shifts most of the tax benefits to borrowers indicative of an elastic supply curve for lenders lenders are compensated for incremental costs such as reductions in tax rates and barriers to entry evidence is also presented that esop lenders are high taxpaying banks suggesting the existence of a tax clientele

market uncertainty correlated and sunspot equilibria in imperfectly competitive economies first version received june 1988 final version accepted november 1990 eds an imperfectly competitive economy is very prone to market uncertainty including uncertainty about the liquidity or thickness of markets we show in particular that there exist stochastic equilibrium outcomes in nonstochastic market games if and only if the endowments are not pareto optimal we also provide a link between extrinsic uncertainty arising in games e g correlated equilibria and extrinsic uncertainty in market economies e g sunspot equilibria a correlated equilibria to the market game is either a sunspot equilibrium or a non sunspot equilibrium to the related securities games but the converse is not true in general

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

the structure of sunspot equilibria the role of multiplicity this paper examines the structure of sunspot equilibria in a standard two period exchange economy with real assets we show that for a generic choice of utility functions and endowments there exists an open set of real asset structures whose payoffs are independent of sunspots such that the economy with this asset structure has a regular sunspot equilibrium an important implication of our result is that the multiplicity of non sunspot equilibria is not necessary for the existence of sunspot equilibria our technique is general and can be applied to show the existence of sunspot equilibria in other frameworks this paper analyses the structure of sunspot equilibria in a standard two period competitive exchange economy with more than one consumption good in each period and a real asset which pays a bundle of commodities there is no uncertainty except for sunspots we show that for an open and dense subset of the set of utility functions and endowments there exists an open set of real asset structures with payoffs independent of sunspots such that the resulting economy with an asset structure in this set has a regular sunspot equilibrium we also show that this result is tight in the space of utility functions endowments and asset structures there is in fact an open set of economies for which sunspot equilibria do not exist moreover our argument provides a systematic method which allows us to find generically all the sunspot equilibria of a given economy thus it can be used as a tool for studying the global structure of the set of sunspot equilibria not just the existence of a sunspot equilibrium the dependence of the existence of sunspot equilibria on the particular specification of the payoff of the asset provides an interesting contrast with the fact that the set of equilibrium allocations of the underlying certainty economy does not depend on the asset structure recall that when markets are complete preferences and endowments completely determine the set of competitive equilibria in our setting markets are complete in the underlying certainty economy so if payoffs change the price of the asset will change accordingly but there is no effect on the equilibrium consumption of the certainty economy thus the fundamentals of the certainty economy are the distribution of endowments and preferences among consumers and our result implies that the existence of sunspot

social networks as a catalyst of economic change abstract this letter finds that east germans with strong social ties invested earlier in a popular new financial product after reunification while long term ownership remained unaffected hence studies of the economic impact of social networks should distinguish transitory from long run effects

conspicuous consumption and political regimes evidence from east and west germany abstract this paper investigates the influence of political regimes on the relative importance of conspicuous consumption we use the division of germany into the communist gdr and the democratic frg and its reunification in 1990 as a natural experiment relying on household data that are representative for germany our empirical results strongly indicate that conspicuous consumption is relatively more important in east germany significantly although we find some convergence a considerable gap in conspicuous consumption expenditures remains even 18 years after the german reunification

correlated equilibrium as an expression of bayesian rationality if it is common knowledge that the players in a game are bayesian utility maximizers who treat uncertainty about other players actions like any other uncertainty then the outcome is necessarily a correlated equilibrium random strategies appear as an expression of each player s uncertainty about what the others will do not as the result of willful randomization use is made of the common prior assumption according to which differences in probability assessments by different individuals are due to the different information that they have where information may be interpreted broadly to include experience upbringing and genetic makeup copyright 1987 by the econometric society

trade and revelation of information abstract we consider an economy with asymmetric information and two types of agents fully informed and uninformed uninformed agents update their information observing equilibrium prices and the equilibrium levels of other agents excess demand we show that for a generic set of economies there are rational expectations equilibria which are partially revealing on an open dense set of signals of positive lebesgue measure provided that the dimension of the signal space is sufficiently larger than the dimension of the commodity space

an economic approach to social capital a standard optimal investment model can be used to analyse an individual s decision to accumulate social capital we analyse six facts that support the predictions of this individual based approach 1 social capital first rises and then falls with age 2 social capital declines with expected mobility 3 social capital rises in occupations with greater returns to social skills 4 social capital is higher among homeowners 5 social connections fall sharply with physical distance 6 people who invest in human capital also invest in social capital we fail to find robust evidence that social capital investments fall with the value of time or that geographic religious groups generate social capital complementarities

capital gains taxation and funding for start ups abstract we examine how capital gains taxes affect investment in private start up i e pre ipo firms using data on capital raised in individual funding rounds we estimate the effect of the 2010 sbja which implemented a full exemption from federal capital gains tax on the sale of qualified shares because of the resulting higher expected after tax returns we hypothesize and find evidence consistent with this capital gains tax reduction increasing the amount of investment in start up firms per funding round by about 12 the effect is stronger in start up firms that are likely to have greater administrative capacity we estimate that about one third of the tax benefit is captured by investors

an exploration of the eductive justifications of the rational expectations hypothesis this paper examines justifications of the rational expectations hypothesis that rely on the analysis of the agents mental forecasting educing activity which involves forecasting the forecasts of others etc the corresponding concept of eductive learning stability based on the game theoretical concept of rationalizability is primarily used within the classical muth model conditions for coordination of beliefs are interpreted and discussed they are robust to the introduction of noise more generally eductive stability fits economic intuition on coordination stability increases when the industry product differentiation increases and when decisions are sequential and observable copyright 1992 by american economic association

rational behavior and rational expectations abstract this paper presents a new definition of rational expectations equilibrium in security markets characterized by a rigorous treatment of the decision problem facing each agent a rational expectations equilibrium is one in which it is common knowledge among the agents that all of them are rational and that the price observed is the market clearing price the paper shows that such equilibria always exist and that they need not have the property that for generic economies the equilibrium price reveals all economically relevant information the paper also shows that the new definition generalizes existing definitions of rational expectations equilibrium

notes on sequence economies transaction costs and uncertainty abstract a sequence economy is an economy with trade at every date and state it is inessential if its equilibria coincide with those of the corresponding arrow debreu economy we examine some of the conditions for essentiality 1 if there are transaction costs then even if all states of nature are spanned by the securities the economy is generically essential 2 in the absence of transaction costs we show by examples that spanning is neither necessary nor suficient for inessentiality the former because some state distinctions may be irrelevant the latter because of possible multiple spot equilibria for a given state 3 we speculate on the possibility that price contingent securities might complete the markets and more generally on the idea of endogenous uncertainty journal of economic literature classification number c62

stochastic equilibria with incomplete financial markets abstract we demonstrate the existence of equilibria with incomplete financial markets for stochastic economies whose information structure is given by an event tree restricting attention to purely financial securities those paying in units of account e g dollars financial markets may be incomplete some consumption streams may be impossible to obtain by any trading strategy securities may be individually precluded from trade at arbitrary states and dates sufficient conditions for the existence of stochastic equilibria are continuous convex strictly monotonic preferences and strictly positive aggregate endowments these conditions are weakened a corollary states that any regime of security prices precluding arbitrage can be embedded in an equilibrium

partial revelation with rational expectations we exhibit a partially revealing rational expectations equilibrium where no individual knows the state of the world or the quantities traded by any other individual c 1998 academic press

the impact of mass migration on the israeli labor market mass migration from the former soviet union increased the israeli population by 12 in the first half of the 1990s this exodus was precipitated by the lifting of emigration restrictions in an unstable ussr and by the open immigration policy of israel toward soviet jews who faced more restrictive entry policies elsewhere i use this natural experiment to study the impact of immigration on the labor market outcomes of native israelis ols yields significant reductions in wages and small reductions in employment however ols is biased if the distribution of immigrants across occupations in israel was not exogenous to relative wage and employment conditions i instrument for the entry of russians into an occupation in israel using information on their former occupations in the ussr there is a significant positive correlation between the former presence of the immigrants in an occupation in the ussr and their presence in that occupation in israel but the previous occupational choices of russians abroad were independent of israeli wage and employment growth subsequent to their migration iv estimates indicate that immigration did not have an adverse impact on native israeli labor market outcomes

the existence of fully rational expectations approximate equilibria with noisy price observations abstract nonrevealing fully rational expectations approximate equilibria exist in microeconomic pure exchange economies in which uninformed agents have suitably dispersed noisy price observations such traders maximize a state dependent expected utility conditional on the price vector they observe the distributions of noisy price observations and the correct equilibrium relationship between states of the world and prices in equilibrium aggregate excess demand is small with high probability in every state of the world and its expectation is also small this magnitude diminishes as the noisy price observations become more accurate equilibria are obtained by applying a fixed point argument to state dependent excess demand functions which are smooth because of the noisy price observations

do capital gain tax rate increases affect individual investors trading decisions abstract this paper examines individual investors short and long term trading reactions to the 1986 tax reform act s tra 86 capital gain tax rate increase consistent with a tax induced trading model we document a december 1986 change in year end trading patterns tra 86 also had long term effects on individual investors trading decisions the results suggest that individual investors were less more willing to sell accrued gain loss stocks after tra 86 our ability to document predicted trading behavior is in part due to our trading metric which captures individual investors selling activity better than the volume based metrics used in prior research

equilibrium in economies with incomplete financial markets abstract this paper analyses an exchange economy in the absence of arrow debreu complete markets it is assumed that trading takes place in the sequence of spot markets and futures markets for securities payable in units of account unlimited short selling in securities is allowed a general equilibrium in such an economy is a set of current and future prices contingent on uncertain events and a set of individual plans such that all markets are cleared the existence of such an equilibrium is proved under usual assumptions this is in contrast to the case of futures markets for contingent futures commodities where an equilibrium may not exist the optimality of equilibrium allocations is also discussed

common knowledge of rationality and market clearing in economies with asymmetric information abstract consider an exchange economy with asymmetric information what is the set of outcomes that are consistent with common knowledge of rationality and market clearing to address this question we define an epistemic model for the economy that provides a complete description not only of the beliefs of each agent on the relationship between states of nature and prices but also of the whole system of interactive beliefs the main result theorem 1 provides a characterization of outcomes that are consistent with common knowledge of rationality and market clearing henceforth ckrmc outcomes in terms of a solution notion ex post rationalizability that is defined directly in terms of the parameters that define the economy ckrmc manifests several intuitive properties that stand in contrast to the full revelation property of rational expectations equilibrium in particular for a robust class of economies 1 there is a continuum of prices that are consistent with ckrmc in every state of nature and hence these prices do not reveal the true state 2 the range of ckrmc outcomes is monotonically decreasing as agents become more informed about the economic fundamentals and 3 trade is consistent with common knowledge of rationality and market clearing even when there is common knowledge that there are no mutual gains from trade

historical origins of firm ownership structure the persistent effects of the african slave trade this paper uses evidence from the historical african slave trade to extend prior theory linking modern firm ownership structure to institutions and social capital we argue that institutions and so

network effects and welfare cultures we empirically examine the role of social networks in welfare participation using data on language spoken at home to better infer networks within an area our empirical strategy asks whether being surrounded by others who speak the same language increases welfare use more for those from high welfare using language groups this methodology allows us to include local area and language group fixed effects and to control for the direct effect of being surrounded by one s language group these controls eliminate many of the problems in previous studies the results strongly confirm the importance of networks in welfare participation

social capital and social quilts network patterns of favor exchange we examine the informal exchange of favors in societies such that any two individuals interact too infrequently to sustain exchange but such that the social pressure of the possible loss of multiple relationships can sustain exchange patterns of exchange that are locally enforceable and renegotiation proof necessitate that all links are supported any two individuals exchanging favors have a common friend in symmetric settings such robust networks are social quilts tree like unions of completely connected subnetworks examining favor exchange networks in 75 villages in rural india we find high levels of support and identify characteristics that correlate with support

generic existence of completely revealing equilibria for economies with uncertainty when prices convey information conditions which imply the existence of strict rational expectations equilibria for most static pure exchange economies where prices convey information about the state of the world are analyzed information is aggregated and transmitted by prices because agents have different initial information and maximize the conditional expectation of state dependent utility functions major results state that if with probability one agents characteristics do not vary too much as the state of the world varies then generically there exist equilibrium price functions which reveal all initial information more precisely if the support of the image measure is contained in a compact c1 manifold satisfying some technical conditions which is of sufficiently low dimension relative to the number of commodities then existence of completely revealing equilibria is generic any economy satisfying these assumptions can be approximated by a sequence of economies which also obey these assumptions and have completely revealing equilibrium price functions slight perturbations do not destroy the existence property

trust and social collateral this paper builds a theory of trust based on informal contract enforcement in social networks in our model network connections between individuals can be used as social collateral to secure informal borrowing we define network based trust as the largest amount one agent can borrow from another agent and derive a reduced form expression for this quantity which we then use in three applications 1 we predict that dense networks generate bonding social capital that allows transacting valuable assets whereas loose networks create bridging social capital that improves access to cheap favors such as information 2 for job recommendation networks we show that strong ties between employers and trusted recommenders reduce asymmetric information about the quality of job candidates 3 using data from peru we show empirically that network based trust predicts informal borrowing and we structurally estimate and test our model

real indeterminacy with financial assets abstract it is shown that in a two period general equilibrium securities model where assets pay in money the generic dimension of the set of equilibrium allocations in the incomplete market situation is s 1 where s is the number of assets hence the degree or real indeterminacy is independent of the number of assets this result requires beyond fewer assets than states that the number of traders be larger than the number of securities and that the asset return matrix be in general position the generic dimension for arbitrary returns matrix is also obtained it is argued in addition that the presence of real or mixed assets does not by itself lower the degree of indeterminacy

empirical tax research in accounting this paper traces the development of archival microeconomic based empirical income tax research in accounting over the last 15 years the paper details three major areas of research i the coordination of tax and non tax factors ii the effects of taxes on asset prices and iii the taxation of multijurisdictional international and interstate commerce methodological concerns of particular interest to this field also are discussed the paper concludes with a discussion of possible directions for future research r 2001 elsevier science b v all rights reserved jel classification m41 h25 k34 g32 f23

correlated equilibria and sunspots we examine when sunspots uncertainty that has no influence on endowments preferences or technology can affect equilibrium in a simple two period two commodity two class economy we find that such an effect is possibly only if the signals random variables that different agents observe are imperfectly correlated neither perfectly correlated nor independent and at least one commodity is a giffen good for two special cases we characterize the set of equilibria due to sunspots we conclude by showing the intimate connection between the sunspot equilibria of our finite horizon model and those of the overlapping generations literature

a tear in the iron curtain the impact of western television on consumption behavior this paper examines the impact of exposure to foreign media on the economic behavior of agents in a totalitarian regime we study private consumption choices focusing on former east germany where differential access to western television was determined by geographic features using data collected after the transition to a market economy we find no evidence of a significant impact of previous exposure to western television on aggregate consumption levels however exposure to western broadcasts affects the composition of consumption biasing choices in favor of categories of goods with high intensity of pre reunification advertisement the effects vanish by 1998

peer monitoring and credit markets a major problem for institutional lenders is ensuring that borrowers exercise prudence in the use of the funds so that the likelihood of repayment is enhanced one partial solution is peer monitoring having neighbors who are in a good position to monitor the borrower be required to pay a penalty if the borrower goes bankrupt peer monitoring is largely responsible for the successful financial performance of the grameen bank of bangladesh and of similar group lending programs elsewhere but peer monitoring has a cost it transfers risk from the bank which is in a better position to bear risk to the cosigner in a simple model of peer monitoring in a competitive credit market this article demonstrates that the transfer of risk leads to an improvement in borrowers welfare

tax planning regulatory capital planning and financial reporting strategy for commercial banks we test whether banks investment and financing policies can be explained by tax status we document changes in bank holdings of municipal bonds in response to changes in tax rules relating to deductibility of interest expense we also document an association between banks marginal tax rates and their investment and financing decisions which is consistent with the existence of tax clienteles however banks do not sort themselves perfectly into investment and financing clienteles because of adjustment costs we posit specific types of transaction cost impediments to tax planning and document that banks apparently trade off these costs against tax planning benefits article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

relative deprivation and migration preferences in this letter we overcome the existing shortages with respect to the assignment of individuals to reference groups and are the first to show that individual aversion to relative deprivation plays a decisive role in shaping migration preferences

the social multiplier aggregate data is often used to make inferences about individual level behavior if there are social interactions in which one person s actions influence his neighbor s incentives or information then these inferences are inappropriate the presence of positive social interactions or strategic complementarities implies the existence of a social multiplier where aggregate relationships will overstate individual elasticities we present a brief model and then estimate the size of the social multiplier in three areas the impact of education on wages the impact of demographics on crime and group membership among dartmouth roommates in these contexts there is a significant social multiplier jel ho jo co

identification of endogenous social effects the reflection problem this paper examines the reflection problem that arises when a researcher observing the distribution of behaviour in a population tries to infer whether the average behaviour in some group influences the behaviour of the individuals that comprise the group it is found that inference is not possible unless the researcher has prior information specifying the compisition of reference groups if this information is available the prospects for inference depend critically on the population relationship between the variables defining reference groups and those directly affecting outcomes inference is difficult to implossible if these variables are functionally dependent or are statistically independent the prospects are better if the variables defining reference groups and those directly affecting outcomes are moderately related in the population

on endogenous formation of price expectations abstract we study a two period exchange economy with complete financial markets and endogenous borrowing constraints contrary to perfect foresight paradigm we assume that agents are heterogeneous in their ability to forecast future prices we introduce a new equilibrium concept called informationally constrained equilibrium where the formation of price expectations is endogenous and reflects the revelation of information from observing bounds on liabilities designed to ensure solvency at any contingency we prove that under standard assumptions an equilibrium always exists and we characterize the degree of information revealed by the endogenous debt limits

the effects of social networks on employment and inequality we develop a model where agents obtain information about job opportunities through an explicitly modeled network of social contacts we show that employment is positively correlated across time and agents moreover unemployment exhibits duration dependence the probability of obtaining a job decreases in the length of time that an agent has been unemployed finally we examine inequality between two groups if staying in the labor market is costly and one group starts with a worse employment status then that group s drop out rate will be higher and their employment prospects will be persistently below that of the other group

the unfinished journey of ecological economics the goal of the economists and ecologists who laid the conceptual foundations for ecological economics in the 1960s and 1970s was to create a scientifically informed discipline that could serve as the basis for coordinating economic activities in environmentally responsible ways the aim of this article is to make a convincing case that the history of neoclassical economic theory provides a coherent basis for understanding why ecological economists must finish the journey begun by these economists and ecologists

portfolio choice exchange rates and indeterminacy consider an exchange economy under uncertainty the asset market is incomplete there are fewer assets a than states of nature s assets are nominal and are denominated in n distinct currencies competitive equilibria are distinct if the associated allocations are distinct an economy displays k degrees of indeterminacy if the set of distinct competitive equilibria contains a k dimensional open set generically the economy displays ns a n 1 n degrees of indeterminacy

non separable time preferences novelty consumption and body weight theory and evidence from the east german transition to capitalism abstract this paper develops a dynamic model to illustrate how diet and body weight change when novel food products become available to consumers we propose a microfounded test to empirically discriminate between habit and taste formation in intertemporal preferences moreover we show that novelty consumption and endogenous preferences can explain the persistent correlation between economic development and obesity by empirically studying the german reunification we find that east germans consumed more novel western food and gained more weight than west germans when a larger variety of food products became readily accessible after the fall of the wall the observed consumption patterns suggest that food consumption features habit formation

cultural proximity and loan outcomes we present evidence that shared codes religious beliefs ethnicity cultural proximity between lenders and borrowers improves the efficiency of credit allocation we identify in group preferential treatment using dyadic data on the religion and caste of bank officers and borrowers from a bank in india and a rotation policy that induces exogenous matching between officers and borrowers cultural proximity increases lending on both intensive and extensive margins and improves repayment performance even after the in group officer is replaced by an out group one further cultural proximity increases loan dispersion and reduces loan to collateral ratios our results imply that cultural proximity mitigates informational problems that adversely affect lending which in turn relaxes financial constraints and improves access to finance

perils of unconventional monetary policy abstract unconventional monetary policy by relaxing restrictions on the composition of the balance sheet of the central bank compromises control over the stochastic path of inflation or in open economies over the stochastic path of exchange rates if the composition of the balance sheet is unrestricted then the path of inflation is indeterminate this is the case under pure quantitative easing where the target is the size of real money balances in contrast credit easing policies restrict the composition of the portfolio by targeting a specific expansion in the maturity profile of bonds bought and thus can implement a determinate path of inflation the composition of the portfolios traded by monetary fiscal authorities also determines premia in asset and currency markets

consumption risk sharing in social networks we develop a model of informal risk sharing in social networks where relationships between individuals can be used as social collateral to enforce insurance payments we characterize incentive compatible risk sharing arrangements and obtain two results 1 the degree of informal insurance is governed by the expansiveness of the network measured by the number of connections that groups of agents have with the rest of the community relative to group size twodimensional networks where people have connections in multiple directions are su ciently expansive to allow very good risk sharing we show that social networks in peruvian villages satisfy this dimensionality property thus our model can explain townsend s 1994 puzzling observation that village communities often exhibit close to full insurance 2 in second best arrangements agents organize in endogenous risk sharing islands in the network where shocks are shared fully within but imperfectly across islands as a result network based risk sharing is local socially closer agents insure each other more

migrants ancestors and foreign investments we use 130 years of data on historical migrations to the u s to show a causal effect of the ancestry composition of u s counties on foreign direct investment fdi sent and received by local firms to isolate the causal effect of ancestry on fdi we build a simple reduced form model of migrations migrations from a foreign country to a u s county at a given time depend on 1 a push factor causing emigration from that foreign country to the entire u s and 2 a pull factor causing immigration from all origins into that u s county the interaction between time series variation in origin specific push factors and destination specific pull factors generates quasi random variation in the allocation of migrants across u s counties we find that doubling the number of residents with ancestry from a given foreign country relative to the mean increases the probability that at least one local firm engages in fdi with that country by 4 percentage points we present evidence that this effect is primarily driven by a reduction in information frictions and not by better contract enforcement taste similarities or a convergence in factor endowments

networks in the modern economy mexican migrants in the u s labor market this paper attempts to identify job networks among mexican migrants in the u s labor market the empirical analysis uses data on migration patterns and labor market outcomes based on a sample of individuals belonging to multiple origin communities in mexico over a long period of time each community s network is measured by the proportion of the sampled individuals who are located at the destination the united states in any year we verify that the same individual is more likely to be employed and to hold a higher paying nonagricultural job when his network is exogenously larger by including individual fixed effects in the employment and occupation regressions and by using rainfall in the origin community as an instrument for the size of the network at the destination

on the existence of rational expectations equilibrium abstract we prove a theorem on the existence of rational expectations general economic equilibrium when agents condition on prices as well as on private information and maximize the expectation of a state dependent utility function the key to the result is a new idealization of what it means for a set of empirical distributions to support agents expectations this idealization depends on the notion that agents compare their expectations with continuous versions of the random empirical distributions that are generated by the workings of the economy the existence theorem covers all strictly concave utility functions arbitrary distributions of the state variable and situations in which the dimension of the state variable is large relative to the number of commodities

endogenous price fluctuations in an optimizing model of a monetary economy this paper demonstrates that an optimizing model of a monetary economy can produce perfect foresight equilibria in which the price level fluctuates forever cyclically or chaotically fluctuating equilibria are more likely to exist when the rate of money supply growth is high furthermore the set of equilibrium prices may have a complicated topological structure which poses a more serious problem concerning the validity of comparative statics method than any sort of indeterminacy previously discussed in the literature copyright 1991 by the econometric society

the revelation of information and self fulfilling beliefs abstract at a rational expectations equilibrium ree individuals are assumed to know the map from states to prices this hypothesis has two components that agents agree consensus and that they have point expectations degeneracy we consider economies where agents beliefs are described by a joint distribution on states and prices and these beliefs are fulfilled at equilibrium beliefs are self fulfilling if every price in the support of the distribution is an equilibrium price the corresponding equilibria are beliefs equilibria be the further restriction that agents have the same beliefs results in common beliefs equilibria cbe we study the relationship between be cbe and ree thus isolating the role of consensus and of degeneracy in achieving rational expectations journal of economic literatureclassification numbers d51 d82

partially revealing rational expectations equilibrium in a competitive economy abstract a class of pure exchange economies is considered in which some agents are informed of private information and others are uninformed existence of a partially revealing rational expectations equilibrium ree is proved without restricting attention to particular functional forms for utility functions and probability distributions without introducing noise into the model and without departing from the standard definition of ree the equilibrium is robust in the sense that if the primitives of the economy are slightly perturbed the economy continues to have a qualitatively similar ree with somewhat stronger assumptions placed on the economy the equilibrium is also the unique measurable ree

the impact of social structure on economic outcomes s ocial structure especially in the form of social networks affects economic outcomes for three main reasons first social networks affect the flow and the quality of information much information is subtle nuanced and difficult to verify so actors do not believe impersonal sources and instead rely on people they know second social networks are an important source of reward and punishment since these are often magnified in their impact when coming from others personally known third trust by which i mean the confidence that others will do the right thing despite a clear balance of incentives to the contrary emerges if it does in the context of a social network economists have recently devoted considerable attention to the impact of social structure and networks on the economy for example see the economists chapters in rauch and casella 2001 and the illuminating review essay of this volume by zuckerman 2003 as well as dutta and jackson 2003 and calvoarmengol 2004 however i focus here on sociologists contributions sociologists have developed core principles about the interactions of social structure information ability to punish or reward and trust that frequently recur in their analyses of political economic and other institutions i begin by reviewing some of these principles building on these i then discuss how social structures and social networks can affect economic outcomes like hiring price productivity and innovation