economies of density versus natural advantage crop choice on the back forty abstract we estimate the factors determining specialization of crop choice at the level of individual fields distinguishing between the role of natural advantage soil characteristics and economies of density scale economies achieved when farmers plant neighboring fields the same using rich geographic data from north dakota including new data on crop choice collected by satellite we estimate a model of how a farmer plants adjacent fields under the farmer s control we find planting decisions on a field are heavily dependent on the soil characteristics of adjacent fields through this relationship we back out the structural parameters of economies of density

developing a stress testing framework based on market risk models the basel 2 accord requires regulatory capital to cover stress tests yet no coherent and objective framework for stress testing portfolios exists we propose a new methodology for stress testing in the context of market risk models that can incorporate both volatility clustering and heavy tails empirical results compare the performance of eight risk models with four possible conditional and unconditional return distributions over different rolling estimation periods when applied to major currency pairs using daily data spanning more than 20 years we find that stress test results should have little impact on current levels of foreign exchange regulatory capital

policy innovation in local jurisdictions testing for neighborhood influence in school choice policies before making difficult decisions individuals tend to collect information on decision makers in reference groups with respect to policy innovations in a decentralized public sector this may give rise to positive neighborhood influence on adoption decisions in this paper u s school district data are used to show that decision makers indeed are heavily affected by decision makers in reference groups the policy innovation under consideration is inter district public school choice the results suggest that if a given district s neighbors expected benefits from adopting school choice policies increase this substantially increases the original district s probability of adoption the paper thus supports the view that the diffusion of policy innovations is stimulated by horizontal interaction among local governments

limit order book as a market for liquidity we develop a dynamic model of an order driven market populated by discretionary liquidity traders these traders must trade yet can choose the type of order and are fully strategic in their decision traders differ by their impatience less patient traders demand liquidity more patient traders provide it three equilibrium patterns are obtained the pattern is determined by three parameters the degree of impatience of the patient traders which we model as the cost of execution delay in providing liquidity their proportion in the population which determines the degree of competition among the liquidity providers and the tick size which is the cost of the minimal price improvement despite its simplicity the model generates a rich set of empirical predictions on the relation between market parameters time to execution and spreads we argue that the economic intuition of this model is so basic its main results must be robust in much more general models

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

liquidity adjusted intraday value at risk modeling and risk management an application to data from deutsche borse abstract this paper develops a high frequency risk measure the liquidity adjusted intraday value at risk livar our objective is to explicitly consider the endogenous liquidity dimension associated with order size by reconstructing the open limit order book of deutsche borse changes in the tick by tick ex ante frictionless return and actual return are modeled jointly the risk related to the ex ante liquidity premium is then quantified our model can be used to identify the impact of ex ante liquidity risk on total risk and to provide an estimation of the var for the actual return at a point in time in our sample liquidity risk can account for up to 32 of total risk depending on order size

communication in repeated games with private monitoring abstract the paper considers repeated games where each player can be observed by only a subset of the other players and where players can make public announcements about the behavior of the players they observed we address the following question what is the minimal level of observability that is required to obtain efficient outcomes the main result is that the limit set of sequential equilibrium payoffs when the discount factor tends to one contains the set of individual rational payoffs whenever each player is observed by at leasttwoother players journal of economic literatureclassification number c73

a review of william easterly s the tyranny of experts economists dictators and the forgotten rights of the poor william easterly marshals yet another brilliant critique of established development policies with a focus on the experts excessive focus on state led policies and goals a la myrdal and ignorance of bottom up solutions including technology and individual rights a la hayek it suggests a world where success occurs in spite of nation states yet not all bottom up leads to success and the worst disasters as in civil violence occur where states fail easterly highlights the important links between success and individual freedom and opportunity he fails to note that myriad impoverished individuals cannot exercise these freedoms due to low expectations or compromised rights

social networks and new product choice to successfully market new products in a social network it is essential to identify influential individuals whose product recommendations influence the consumption choices of their peers in this study we use spatial econometric methods to determine how individuals revise their preferences for product attributes when exposed to product recommendations from peers and how different individuals who vary in their degree of network connectedness exert influence on the product choices of others we find evidence that consumers look to others for guidance from peers in their preference for subjective taste specific parameters but tend not to respond to peer price choices our spatial methods allow us to empirically determine the influence exerted by individual members on the consumption choices of other members of the social network we find that connected members of the social network are not always the most influential in revising the consumption choices of others our estimates reveal that network proximity explains only 8 8 of influence

public goods in networks this paper considers incentives to provide goods that are non excludable along social or geographic links we find first that networks can lead to specialization in public good provision in every social network there is an equilibrium where some individuals contribute and others free ride in many networks this extreme is the only outcome second specialization can benefit society as a whole this outcome arises when contributors are linked collectively to many agents finally a new link increases access to public goods but reduces individual incentives to contribute hence overall welfare can be higher when there are holes in a network

religious participation and children s education a social capital approach abstract based on the argument in both economic and sociological literature that religion is conducive to children s human capital formation this paper provides a model of religious participation and explores a mechanism that social capital affects children s education a la coleman coleman j s 1988 social capital in the creation of human capital american journal of sociology 94 s95 s120 the model generates several interesting implications which help explain some important stylized facts about education and religion further in a dynamic setting the model shows that there exists a steady state in which individuals allocate a positive amount of time and resources to religious activities thus it complements the existing literature to explain why seemingly unproductive religions can be everlasting

the effect of group size on public good provision in a repeated game setting abstract the ability to cooperate in the provision of a pubic good is analyzed in a repeated game holding the level of provision fixed with quasi linear utility we find that the critical value of the discount parameter converges to 0 in the limit thus cooperation is feasible in a large market next we allow the level cooperation to be adjusted optimally as the group size increases both for a specific form of quasi linear utility and for cobb douglas utility in each case we find that there are admissible values of the discount parameter such that cooperation may be maintained in the limit

estimating ethnic preferences using ethnic housing quotas in singapore there are many policies around the world aimed at integrating groups gender ethnic national in education employment immigration and housing in the case of housing since prices may not internalize externalities in residential location choices we need to know preferences for welfare analysis this paper estimates people s taste for living with own ethnic groups ethnic preferences using unique policy variation from the ethnic housing quotas in singapore my approach combines policy induced variation commonly used in reduced form settings with a non parametric identi cation strategy in a structural demand estimation framework a la berry levinsohn and pakes 1995 i nd that all groups have strong preferences to live with at least some other

so what orders do informed traders use we present a simple glosten milgrom type equilibrium model to analyze the decision of informed traders on whether to use limit or market orders we show that even after incorporating an order s price impact not only may informed traders prefer to use limit orders but the probability that they submit limit orders can be so high that limit orders convey more information than market orders we further show that the horizon of the private information is critical for this decision and is positively related to the use of limit orders our empirical analysis using torq suggests that informed traders do prefer limit orders to market orders and that limit orders are indeed more informative our model is in contrast to the literature that assumes that informed traders use market orders only and the literature that examines the limit order versus the market order decision of uninformed traders

imitation contagion or exertion using a tax reform to reveal how colleagues sick leaves influence worker behaviour we analyse the social interaction effects in sick leave behaviour in the workplace using high quality norwegian matched employer employee data with detailed individual information on sick leaves during the 2004 2006 period we find that social interaction effects in sick leave behaviour in the workplace do exist and that the effects are noticeable in size the strong relationship between the sick leave rates among colleagues is not solely the result of contagious diseases nor is it caused by improved informational quality or by the increased workload for the non absent workers evidence supports the existence of reciprocal worker behaviour that is unrelated to joint leisure seeking activities

social interaction and conformism in a random utility model abstract we analyze a class of dynamic binary choice models with social interaction agents are heterogeneous and their degree of conformism taste externality changes over time endogenously we show that social interaction in itself is not enough to observe multiple equilibria and that the equilibrium outcome is not necessarily a polarized society the social outcome depends on the law of motion that drives the evolution of taste externality

set identification in models with multiple equilibria we propose a computationally feasible way of deriving the identified features of models with multiple equilibria in pure or mixed strategies it is shown that in the case of shapley regular normal form games the identified set is characterized by the inclusion of the true data distribution within the core of a choquet capacity which is interpreted as the generalized likelihood of the model in turn this inclusion is characterized by a finite set of inequalities and efficient and easily implementable combinatorial methods are described to check them in all normal form games the identified set is characterized in terms of the value of a submodular or convex optimization program efficient algorithms are then given and compared to check inclusion of a parameter in this identified set the latter are illustrated with family bargaining games and oligopoly entry games copyright 2011 oxford university press

waves in consumption with interdependence among consumers this paper presents a model to analyze the development of consumption patterns when there are social interactions among consumers in particular a consumer in this model recognizes three reference groups a peer group of similar consumers with whom the consumer wishes to share consumption activities a distinction group from which the consumer wishes to distinguish him or herself and an aspiration group to which the consumer does not belong but wishes that he she did and with whom the consumer would like to share consumption activities the interplay of aspiration and distinction can lead to waves in consumption these can happen when for example the avant garde consumption of up market pioneers is copied by other types of consumer as the latter aspire to emulate the former the former in turn seek to distinguish themselves from these unwelcome companions by varying their consumption in consequence a particular consumption activity may start up market an then gradually proceed down the social spectrum more complex patterns with continuing cycles in consumption can also be found the paper argues that this model is not only applicable to the consumption behaviour of an elite or would be elite but is relevant in a wide range of consumption settings

neighborhood effects in integrated social policies when potential beneficiaries share their knowledge and attitudes about a policy intervention their decision to participate and the effectiveness of both the policy and its evaluation may be influenced this matters most notably in integrated social policies with several components in this article spillover effects on take up behaviors are investigated in the context of a conditional cash transfer program in rural mexico these effects are identified using exogenous variations in the local frequency of beneficiaries generated by the program s randomized evaluation a higher treatment density in the areas surrounding the evaluation villages is found to increase the take up of scholarships and enrollment at the lower secondary level these cross village spillovers operate exclusively within households receiving another component of the program and do not carry over larger distances while several tests reject heterogeneities in impact due to spatial variations in program implementation evidence is found suggesting that spillovers stem partly from the sharing of information about the program among eligible households

peers at work we study peer effects in the workplace specifically we investigate whether how and why the productivity of a worker depends on the productivity of coworkers in the same team using high frequency data on worker productivity from a large supermarket chain we find strong evidence of positive productiv ity spillovers from the introduction of highly productive personnel into a shift worker effort is positively related to the productivity of workers who see him but not workers who do not see him additionally workers respond more to the presence of coworkers with whom they frequently interact we conclude that social pressure can partially internalize free riding externalities that are built into many workplaces jel j24 l81 m54

people s opium religion and economic attitudes since max weber there has been an active debate on the impact of religion on people s economic attitudes much of the existing evidence however is based on cross country studies in which this impact is confounded by differences in other institutional factors we use the worldvalues surveys to id entify the relationship between intensity of religious beliefs and economic attitudes controlling for country fixed effects we study several economic attitudes towardcooperation the government working women legal rules thriftiness andthe market economy we also distinguish across religious denominations differentiating on whether a religion is dominant in a country we find that on average religious beliefs are associated with good economic attitudes where good is defined as conducive to higher per capita income andgrowth yet religious people tendto be more racist andless favorable with respect to working women these effects differ across religious denominations overall we find that christian religions are more positively associatedwith attitudes conducive to economic growth r 2003 elsevier science b v all rights reserved jel classification a1 e0 n4 z1

intrinsic heterogeneity in expectation formation we introduce the concept of misspecification equilibrium to dynamic macroeconomics agents choose between a list of misspecified econometric models and base their selection on relative forecast performance a misspecification equilibrium is a stochastic process in which agents forecast optimally given their choices with forecast model parameters and predictor proportions endogenously determined under appropriate conditions the misspecification equilibrium will exhibit intrinsic heterogeneity in which all predictors are used at all times even in the neoclassical limit in which only the most successful predictors are used this equilibrium is attainable under least squares learning and dynamic predictor selection based on average profits

crime and social interactions the high variance of crime rates across time and space is one of the oldest puzzles in the social sciences this variance appears too high to be explained by changes in the exogenous costs and benefits of crime we present a model where social interactions create enough covariance across individuals to explain the high cross city variance of crime rates this model provides an index of social interactions which suggests that the amount of social interactions is highest in petty crimes moderate in more serious crimes and almost negligible in murder and rape

ethnic diversity social sanctions and public goods in kenya abstract this paper examines ethnic diversity and local public goods in rural western kenya the identification strategy relies on the stable historically determined patterns of ethnic land settlement ethnic diversity is associated with lower primary school funding and worse school facilities and there is suggestive evidence that it leads to poor water well maintenance the theoretical model illustrates how inability to impose social sanctions in diverse communities leads to collective action failures and we find that school committees in diverse areas do impose fewer sanctions on defaulting parents we relate these results to the literature on social capital and economic development and discuss implications for decentralization in less developed countries

how family networks drive residential location choices evidence from a stated preference field experiment in bogota colombia this research quantifies the relative importance of proximity to extended family networks in the stated residential location choices of bogota s low to middle income residents by applying a conditional logistic regression model and using data from an original choice experiment i find that the surveyed individuals prefer living near their extended family and on average prioritise it more than accessibility to the central business district those who have relied on help from extended family members in a personal or economic crisis situation have a stronger preference for living near extended family compared with those who have not as do those who are able to rely on extended family ties for childcare assistance

understanding regression versus variance tests for social interactions this article considers the relationship between the use of regressions and the use of variance contrast methods to uncover social interactions we illustrate how these methods employ different identifying assumptions and are therefore complementary approaches we also provide formal identification results that extend existing ones for the two methods jel c12 c21 c23 z13 this article is designed to understand the relationshipbetweentwoapproachestotheempirical analysis of social interactions the first approach is the use of linear regressions to uncover social interactions this approach estimates social interaction effects through changes in the conditional linear expectation of individual outcomes when group level variables are included in the conditioning set in econometrics this method was first analyzed by manski 1993 who dubbed it the linearin means model since the group level variables are typically averages of individual variables within the group this model is also studied by brock and durlauf 2001a 2001b cohencole 2006 and graham and hahn 2005 among others durlauf 2004 surveyed empirical studiesof social interactionsbasedonsuch regressions the second approach originally proposed by glaeser sacerdote and scheinkman 1996 and developed into a full inferential procedure by graham 2005 who refers to this approachasvariancecontrasts usesintragroup variation in behavior to infer social interactions the idea in this approach is that social interactions willinduceintragroupdependences in behavior that affect sample variances for intragroup outcomes there has been relatively little work evaluating social interactions using variance contrasts one reason is that with the exception of graham s work there is little formal statistical theory for the approach the purpose of this article was to clarify the relationship between regression and variance contrast tests weclarify how these tests employ different informational assumptions to achieve identification of social interaction specifically we argue that regression and variance contrast approaches correspond to identification via exclusion restrictions in the one case and covariance restrictions on errors in the other as such the two approaches replicate the classes of identification strategies that appear in the classical simultaneous equations literature see fisher 1966 for a classic treatment the remainder of the article is organized as

spatial externalities in agriculture empirical analysis statistical identification and policy implications summary spatial externalities can affect economic welfare and landscape pattern by linking farm returns on adjoining parcels of land while policy can be informed by research that documents spatial externalities statistically quantifying the presence of externalities from landscape pattern is insufficient for policy guidance unless the underlying cause of the externality can be identified as positive or negative this article provides a springboard for empirical research by examining the underlying structure social environmental interactions and statistical identification strategies for the analysis and the quantification of agricultural spatial externalities that are derived from observations of landscape change the potential for original policy treatments of agricultural spatial externalities in development and environment outcomes is highlighted

the population problem theory and evidence this study is concerned with the relationships among population growth poverty and environmental degradation with particular focus on the situation in developing countries the author rejects the concept of a general theory of fertility behavior in favor of an interpretation of these relationships which might be applicable to certain situations in the poorest parts of the indian subcontinent and sub saharan africa such situations include unacceptable risks of maternal death for poor illiterate women and a condemnation to extreme poverty in conditions of the deterioration of local resources and of the environment the author concludes that population growth rates are too high in certain specific areas and that an appropriate policy reaction to such conditions would be to try to change the options that men and women face so that their reasoned choice would be to lower their fertility

sickness absence and local benefit cultures in many countries sickness absence financed by generous insurance benefits is an important concern in the policy debate there are strong variations in absence behavior among local geographical areas such variations are difficult to explain in terms of observable socioeconomic factors in this paper we investigate whether such variations are related to group effects in the form of social interaction among individuals within neighborhoods well known methodological problems arise when trying to answer this question a special feature of our efforts to deal with these problems is that we adopt several alternative approaches to identify group effects our study is based on a rich set of swedish panel data and we find indications of group effects in each of our approaches

communication in repeated games with imperfect private monitoring this paper examines repeated games in which each player observes a private and imperfect signal on the actions played and in which players are allowed to communicate using public messages providing incentives for players to reveal their observations generates revelation constraints that combined with signal imperfections may be a source of inefficiencies however by delaying the revelation of their observations players may economize on the cost of deterring deviations and thereby avoid these inefficiencies because a player would not want to trigger a sanction that would penalize him too revelation constraints also tend to make sanctions difficult to enforce however with at least three players detecting deviations may not require that all the players reveal their observations in that case we obtain a nash threat version of the folk theorem with two players we do not obtain a similar result nevertheless we show that an efficient outcome can almost always be approximated

discrete choice with social interactions this paper provides an analysis of aggregate behavioural outcomes when individual utility exhibits social interaction effects we study generalized logistic models of individual choice which incorporate terms reflecting the desire of individuals to conform to the behaviour of others in an environment of noncooperative decisionmaking laws of large numbers are generated in such environments multiplicity of equilibria in these models which are equivalent to the existence of multiple self consistent means for average choice behaviour will exist when the social interactions exceed a particular threshold local stability of these multiple equilibria is also studied the properties of the noncooperative economy are contrasted with the properties of an economy in which a social planner determines the set of individual choices finally a likelihood function based on the theoretical model is given and conditions for the econometric identifiability of the model are established

the allocation of future business dynamic relational contracts with multiple agents we consider how a firm dynamically allocates business among several suppliers to motivate them in a relational contract the firm chooses one supplier who exerts private effort output is non contractible and each supplier observes only his own relationship with the principal in this setting allocation decisions constrain the transfers that can be promised to suppliers in equilibrium consequently optimal allocation decisions condition on payoff irrelevant past performance to make strong incentives credible we construct a dynamic allocation rule that attains first best whenever any allocation rule does this allocation rule performs strictly better than any rule that depends only on payoff relevant information

cooperation with network monitoring this paper studies the maximum level of cooperation that can be sustained in perfect bayesian equilibrium in repeated games with network monitoring where players observe each other s actions either perfectly or not at all the foundational result is that the maximum level of cooperation can be robustly sustained in grim trigger strategies if players are equally well monitored comparative statics on the maximum level of cooperation are highly tractable

sanctions in networks the most unkindest cut of all the extensive literature on sanctions has mainly focused on a dyadic interaction between sender and target in contrast this paper examines sanctions when the sender and target are embedded in a network of linkages to other agents the sender can assemble a sanctioning coalition of neighbors to sever their links execute multi link cuts to the target and her allies efficacy of sanctions is now crucially dependent on the network architecture we characterize the structural properties of networks in which a sender can effectively sanction a target in the short run when links can only be deleted and the long run when links can be both deleted and added

dynamic instability of a mixed city in the presence of neighborhood externalities it has been often asked whether a city currently accommodating a variety of economic social and racial groups will continue to be a mixed city or will become exclusively occupied by a single group particularly poor blacks with all other groups moving out of the city in the long run in order to answer this question properly it seems essential to develop a long run dynamic model of a city with emphasis on socioeconomic factors like neighborhood externalities within or among various groups of residents as well as spatial factors like the individual choice of residential space and location it might be safely said that in the literature the only theoretical work which employs a long run dynamic approach to this kind of problem is a paper on dynamic models of segregation by thomas schelling 197 1 although his socioeconomic analysis has revealed some of the dynamic properties of a racially mixed area with neighborhood externalities his model itself is quite unsatisfactory from the economic point of view since it lacks individual utility functions and thereby disregards the aspect of the individual choice of space and location within the city 2 as a result he failed to analyze the effect of spatial segregation within the city on the long run nature of the residential composition of the city in this paper i develop a long run dynamic model of an open city which accommodates two groups of households for example blacks and whites rich and poor young and old with their utility functions depending on a consumption good and residential space i also assume two kinds of neighborhood externalities the first is called negative intergroup externalities that is the utility level of a typical household in one group is adversely affected by an increase in the number of households in the other group living in the city the second is called positive intragroup externalities that is the utility level of a typical household in one group is positively affected by an increase in the size of its own group in in the city first i define a mixed city equilibrium as a long run equilibrium which allows the two groups to coexist in the city in the long run and then introduce a dynamic adjustment process of household movement into and out of the city it is proved that the mixed city equilibrium is always unstable in the presence of negative intergroup externalities and or positive intragroup externalities if residential land is perfectly homogeneous and there is no differential transport cost incurred within the city it turns out however that in the case of a monocentric city with positive transport cost the mixed city equilibrium may be stable or unstable depending on the degree of neighborhood externalities because of the stabilizing effect of spatial segregation between the two groups within the city

how to grow a bubble a model of myopic adapting agents abstract we present a simple agent based model to study the development of a bubble and the consequential crash and investigate how their proximate triggering factor might relate to their fundamental mechanism and vice versa our agents invest according to their opinion on future price movements which is based on three sources of information i public information i e news ii information from their friendship network and iii private information our bounded rational agents continuously adapt their trading strategy to the current market regime by weighting each of these sources of information in their trading decision according to its recent predicting performance we find that bubbles originate from a random lucky streak of positive news which due to a feedback mechanism of these news on the agents strategies develop into a transient collective herding regime after this self amplified exuberance the price has reached an unsustainable high value being corrected by a crash which brings the price even below its fundamental value these ingredients provide a simple mechanism for the excess volatility documented in financial markets paradoxically it is the attempt for investors to adapt to the current market regime which leads to a dramatic amplification of the price volatility a positive feedback loop is created by the two dominating mechanisms adaptation and imitation which by reinforcing each other result in bubbles and crashes the model offers a simple reconciliation of the two opposite herding versus fundamental proposals for the origin of crashes within a single framework and justifies the existence of two populations in the distribution of returns exemplifying the concept that crashes are qualitatively different from the rest of the price moves

habits peers and happiness an evolutionary perspective the principal motivating factor in our lives is the pursuit of happiness in most cultures when seeking this end individuals place a high priority on income and spend much of their waking time procuring this intermediate goal the connection between income and happiness is by no means trivial however two critical factors come into play first beyond subsistence level the positive effect of a permanent change in income tends to be short lived we rapidly become accustomed to a more expensive lifestyle a common name for this feature is habit formation second the satisfaction derived from a given level of income is sharply dependent on how it compares to the income of peers see for example andrew b abel 1990 becker 1996 and william a brock and steven n durlauf 2001 for a demonstration of the influence of habits and peer comparisons over behavior and see shane frederick and george loewenstein 1999 for a review of the underlying psychology habits and peer comparisons mean that an individual is not concerned mainly with her absolute level of income but rather with the difference between her income and a benchmark that changes over time in recent years economists have become increasingly interested in this fact this interest has been both applied i e the study of habits and peer influences over behavior and the analysis of happiness surveys and theoretical i e a search for biological foundations but unlike other more developed areas of economics these two approaches remain fairly separate from each other in particular the existing theoretical work is motivated only by the most basic empirical observations and the existing applied work for the most part has not been influenced by theoretical results in this essay we seek to reduce the distance between these two literature strands in particuhabits peers and happiness an evolutionary perspective

peaceful coexistence the role of religious schools and ngos in the growth of female secondary schooling in bangladesh abstract bangladesh rural advancement committee brac a non governmental organisation ngo runs a large number of non formal primary schools in bangladesh which target out of school children from poor families these schools are well known for their effectiveness in closing the gender gap in primary school enrolment on the other hand registered non government secondary madrasas or islamic schools today enrol one girl against every boy student in this article we document a positive spillover effect of brac schools on female secondary enrolment in registered madrasas drawing upon school enrolment data aggregated at the region level we first show that regions that had more registered madrasas experienced greater secondary female enrolment growth during 1999 2003 holding the number of secular secondary schools constant in this context we test the impact of brac run primary schools on female enrolment in registered madrasas we deal with the potential endogeneity of placement of brac schools usin

some evolutionary foundations for price level rigidity this paper shows that price rigidity evolves in an economy populated by imperfectly rational agents who experiment with alternative rules of thumb in the model firms must set their prices in face of aggregate demand shocks their payoff depends on the level of aggregate demand as well as on their own price and their neighbor s price the latter assumption captures local interactions despite the fact that the rational expectations equilibrium ree is characterized by a simple pricing rule that firms can easily adopt the economy does not converge to the ree for all parameter values when the volatility of monetary innovations is low and interactions among firms are high the aggregate price level exhibits rigidity in that it does not fully react to contemporaneous aggregate demand shocks we discuss the role of the nature of experimentation and of path dependence driven by interactions in explaining these results

a few bad apples spoil the barrel an anti folk theorem for anonymous repeated games with incomplete information we study anonymous repeated games where players may be commitment types who always take the same action we establish a stark anti folk theorem if the distribution of the number of commitment types satisfies a smoothness condition and the game has a pairwise dominant action this action is almost always taken this implies that cooperation is impossible in the repeated prisoner s dilemma with anonymous random matching we also bound equilibrium payoffs for general games our bound implies that industry profits converge to zero in linear demand cournot oligopoly as the number of firms increases

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

equity and efficiency in human capital investment the local connection a general model of community formation and human capital accumulation with social spillovers and decentralized school funding is used to analyse the causes of economic segregation and its consequences for equity and efficiency significant polarization arises from minor differences in endowments preferences or access to capital markets this makes income inequality more persistent across generations but the same need not be true for wealth equilibrium stratification tends to be excessive resulting in low aggregate surplus whether state equalization of school resources can remedy these problems hinges on how purchased social and family inputs interact in education and in mobility decisions

community enforcement of trust with bounded memory we examine how trust is sustained in large societies with random matching when records of past transgressions are retained for a finite length of time to incentivize trustworthiness defaulters should be punished by temporary exclusion however it is profitable to trust defaulters who are on the verge of rehabilitation with perfect bounded information defaulter exclusion unravels and trust cannot be sustained in any purifiable equilibrium a coarse information structure that pools recent defaulters with those nearing rehabilitation endogenously generates adverse selection sustaining punishments equilibria where defaulters are trusted with positive probability improve efficiency by raising the proportion of likely re offenders in the pool of defaulters

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

peer discipline and incentives within groups abstract we investigate how a collusive group can sustain non nash actions by enforcing internal discipline through costly peer punishment we give a simple and tractable characterization of schemes that minimize discipline costs while preserving incentive compatibility we apply the model to a public goods contribution problem we find that if the per capita benefit from the public good is low then regardless of whether peer discipline is feasible or not only small groups will contribute to the good if the public good benefit is significant but peer discipline is infeasible it remains the case that only small groups contribute on the other hand if the public good benefit is significant but peer discipline is feasible then full contribution takes place regardless of group size we reconcile this result with olson s idea that small groups are more effective by considering the case where the per capita benefit of the public good varies with group size

do liquidity measures measure liquidity abstract given the key role of liquidity in finance research identifying high quality proxies based on daily as opposed to intraday data would permit liquidity to be studied over relatively long timeframes and across many countries using new measures and widely employed measures in the literature we run horseraces of annual and monthly estimates of each measure against liquidity benchmarks our benchmarks are effective spread realized spread and price impact based on both trade and quote taq and rule 605 data we find that the new effective realized spread measures win the majority of horseraces while the amihud 2002 illiquidity and stock returns cross section and time series effects journal of financial markets 5 31 56 measure does well measuring price impact

coordination commitment and enforcement the case of the merchant guild we interpret historical evidence in light of a repeated game model to conclude that merchant guilds emerged during the late medieval period to allow rulers of trade centers to commit to the security of alien merchants the merchant guild developed the theoretically required attributes secured merchants property rights and evolved in response to crises to extend the range of its effectiveness contributing to the expansion of trade during the late medieval period we elaborate on the relations between our theory and the monopoly theory of merchant guilds and contrast it with repeated game theories that provide no role for formal organization

a discrete choice model with social interactions with an application to high school teen behavior we develop an empirical discrete choice interaction model with a finite number of agents we characterize its equilibrium properties in particular the correspondence between interaction strength number of agents and the set of equilibria and propose to estimate the model by means of simulation methods in an empirical application we analyze the individual behavior of high school teenagers in almost 500 school classes from 70 schools in our baseline model endogenous social interaction effects are strong for behavior closely related to school truancy somewhat weaker for behavior partly related to school smoking cell phone ownership and moped ownership and absent for behavior far away from school asking parents permission for purchases intra gender interactions are generally much stronger than cross gender interactions in a model with school specific fixed effects social interaction effects are insignificant with the exception of intra gender interactions for truancy copyright c 2007 john wiley sons ltd

why the west became wild informal governance with incomplete networks settlers flocking to boomtowns on the american western frontier were faced with the same task that communities in weak states across the globe face in contemporary times self governance peer sanctions can enforce cooperation in these environments but their efficacy depends on the social networks that transmit information from peer to peer the author uses a game theoretic model to show that peripheral network positions can generate such strong incentives to misbehave that persistent cheating occurs in equilibrium the model reveals that groups maintaining high levels of cooperation that face shocks to their strategic environment or to their network can ratchet down into less cooperative equilibria in which the most peripheral become ostracized furthermore population change that features rapid growth high turnover and enclave settlements can undermine cooperation the insights from this article help to explain the trajectory of cooperation in the mining towns of the wild west in which high levels of cooperation deteriorated as the population surged and help to make sense of why only certain nonwhite settlers were targets of hostility and racism

contagion and uninvadability in local interaction games the bilingual game and general supermodular games abstract in a setting where an infinite population of players interact locally and repeatedly we study the impacts of payoff structures and network structures on contagion of a convention beyond 2 2 coordination games first we consider the bilingual game where each player chooses one of two conventions or adopts both i e chooses the bilingual option at an additional cost for this game we completely characterize when a convention spreads contagiously from a finite subset of players to the entire population in some network and conversely when a convention is never invaded by the other convention in any network we show that the pareto dominant risk dominant resp convention is contagious if the cost of bilingual option is low high resp furthermore if the cost is in a medium range both conventions are each contagious in respective networks and in particular the pareto dominant convention is contagious only in some non linear networks second we consider general supermodular games and compare networks in terms of their power of inducing contagion we show that if there is a weight preserving node identification from one network to another then the latter is more contagion inducing than the former in all supermodular games

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

preference heterogeneity in the structural estimation of efficient pigovian incentives for insecticide spraying to reduce malaria this paper bridges the theoretical and empirical literatures on the role of preference heterogeneity in characterizing externalities related to disease transmission we use a theoretical structure similar to locational sorting models which characterize equilibria in terms of marginal individuals who are indifferent between locations in our case the locations are binary consisting of whether or not to take a discrete preventative action individual heterogeneity arises in this structure due to variation in the costs and disutility associated with prevention we demonstrate application of this approach in the context of participation in insecticide based indoor residual spraying programs for malaria control in northern uganda we identify the parameters of our theoretical model using a stated preference choice experiment combined with estimates from published epidemiological studies the model implies that pigovian subsidies for participation in this context should decrease household malaria risk by 19 25 our approach can be applied to other bioeconomic externalities with spillovers from discrete preventative actions including agricultural pest management and the control of pest infestations and invasive species

collective reputation social norms and participation this paper analyzes a repeated games model of collective reputation with imperfect public monitoring and perfect local peer monitoring of efforts even when peer monitoring is local firms may achieve higher profits under collective reputation by decreasing the cost of maintaining customers trust the optimal number of firms that share a common reputation is greater when 1 trades are more frequent and public information is disseminated more rapidly 2 the deviation gain is smaller compared to the quality premium 3 customers information regarding firms quality is more precise or 4 intragroup information about firms quality is more global from a positive perspective we suggest how social norms can influence the reputation of regional products we also offer an efficiency explanation for food scares from a normative point of view in our model protection of geographical indications increases and mandatory traceability decreases welfare and incentives to provide quality without taking into account direct implementation costs copyright 2012 oxford university press

school segregation and the identification of tipping behavior we develop a method to empirically implement the schelling model of segregation and use it to study racial segregation in los angeles schools from 1995 to 2012 our two step method combines the estimation of parents preferences for their children s peers with a counterfactual simulation analysis we find substantial heterogeneity in the existence and locations of tipping points and stable equilibria schools are observed on equilibrium trajectories but many remained out of equilibrium by 2012 we also introduce novel instrumental variables to identify preferences for endogenous peer groups that require no additional data and can be used in other educational settings

modeling choice interdependence in a social network this paper investigates how individuals product choices are influenced by the product choices of their connected others and how the influence mechanism may differ for fashion versus technology related products we conduct a novel field experiment to induce and observe choice interdependence in a closed social network in our experiment we conceptualize individuals choices to be driven by multiattribute utilities and we measure their initial attribute preferences prior to observing their choice interdependence and collecting network information these design elements help alleviate concerns in identifying social interaction effects from other confounds given that we have complete information on choices and their sequence we use a discrete time markov chain model nonetheless we also use a markov random field mrf model as an alternative when the information on choice sequence is missing we find significant social interaction effects our findings show that whereas experts exert asymmetrically gre

sanctions in networks abstract in this paper we contribute to the sender target models of sanctions by explicitly incorporating the linkages social political or economic that bind the sender and target to other agents given any network model and architecture we draw attention to two factors that play a key role in determining the efficacy of sanctions in reducing the frequency of violations these are respectively strategic complementaritiesbetween the sanctioning action deleting link with target and number of direct links of the sender and the externalities imposed on the sender by third parties we examine the role played by these factors both in the short run when links can only be deleted and the long run when links can also be added as well as when sanctions are unilateral the sender can only delete own links or multilateral the sender can impose on common allies to sever links to the target our analysis allows an active role to the target to build an opposing coalition to deflect sanctions and to third parties to engage in sanction busting it also extends to multiple senders and targets existence of interest groups within sender and target with dissimilar objectives and signed networks allowing both antagonistic and cordial bilateral relationships

cultural integration and its discontents a community s culture is defined by the preferences and equilibrium behaviours of its members contacts among communities alter individual cultures through two interrelated mechanisms behavioural adaptations driven by pay offs to coordination and preference changes shaped by socialization and self persuasion this paper explores the workings of these mechanisms through a model of cultural integration in which preferences and behaviours vary continuously it identifies a broad set of conditions under which cross cultural contacts promote cultural hybridization the analysis suggests that policies to support social integration serve to homogenize preferences across communities thereby undermining a key objective of multiculturalism yielding fresh insights into strategies pursued to influence cultural trends it also shows that communities benefit from having other communities adjust their behaviours

presidential address social transmission bias in economics and finance i discuss a new intellectual paradigm social economics and finance the study of the social processes that shape economic thinking and behavior this emerging field recognizes that people observe and talk to each other a key underexploited building block of social economics and finance is social transmission bias systematic directional shift in signals or ideas induced by social transactions i use five fables models to illustrate the novelty and scope of the transmission bias approach and offer several emergent themes for example social transmission bias compounds recursively which can help explain booms bubbles return anomalies and swings in economic sentiment

rationalizability learning and equilibrium in games with strategic complementarities we study a rich class of noncooperative games that includes models of oligopoly competition macroeconomic coordination failures arms races bank runs technology adoption and diffusion r d competition pretrial bargaining coordination in teams and many others for all these games the sets of pure strategy nash equilibria correlated equilibria and rationalizable strategies have identical bounds also for a class of models of dynamic adaptive choice behavior that encompasses both best response dynamics and bayesian learning the players choices lie eventually within the same bounds these bounds are shown to vary monotonically with certain exogenous parameters we study the class of noncooperative supermodular games introduced by topkis 1979 and further analyzed by vives 1985 1989 who also pointed out the importance of these games in industrial economics supermodular games are games in which each player s strategy set is partially ordered the marginal returns to increasing one s strategy rise with increases in the competitors strategies so that the game exhibits strategic complementarity 2 and if a player s strategies are multidimensional marginal returns to any one com ponent of the player s strategy rise with increases in the other components this class turns out to encompass many of the most important economic applications of noncooperative game theory in macroeconomics diamond s 1982 search model and bryant s 1983 1984 rational expectations models can be represented as supermodular games in each of these models more activity by some members of the economy raises the returns to increased levels of activity by others in oligopoly theory some models of bertrand oligopoly with differentiated products qualify as supermodu lar games in these games when a firm s competitors raise their prices the marginal profitability of the firm s own price increase rises a similar structure is present in games of new technology adoption such as those of dybvig and spatt 1983 farrell and saloner 1986 and katz and shapiro 1986 when more users hook into a communication system or more manufacturers adopt an interface standard the marginal return to others of doing the same often rises similarly in some specifications of the bank runs model introduced by diamond and dybvig 1983 when more depositors withdraw their funds from a bank it is more worthwhile for other depositors to do the same in the warrant exercise

quantifying equilibrium network externalities in the ach banking industry we seek to estimate the causes and magnitudes of network externalities for the automated clearinghouse ach electronic payments system using a panel data set on individual bank usage of ach we construct an equilibrium model of consumer and bank adoption of ach in the presence of a network the model identifies network externalities from correlations of changes in usage levels for banks within a network from changes in usage following changes in market concentration or sizes of competitors and from adoption decisions of banks outside the network with small branches in the network and can separately identify consumer and bank network effects we structurally estimate the parameters of the model by matching equilibrium behavior to the data using simulated maximum likelihood and a data set of localized networks and use a bootstrap to recover confidence intervals the parameters are estimated with high precision and fit various moments of the data reasonably well we find that most of the impediment to ach adoption is due to large consumer fixed costs of adoption the deadweight loss from the network externality is moderate the optimal number of ach transactions is about 16 higher than the equilibrium level

religious schools social values and economic attitudes evidence from bangladesh this paper uses new data on female graduates of registered secondary secular schools and madrasas from rural bangladesh and tests whether there exist attitudinal gaps by school type and what teacher specific factors explain these gaps even after controlling for a rich set of individual family and school traits we find that madrasa graduates differ on attitudes associated with issues such as working mothers desired fertility and higher education for girls when compared to their secular schooled peers on the other hand madrasa education is associated with attitudes that are still conducive to democracy we also find that exposure to female and younger teacher is associated with more favorable attitudes among graduates

failure of gradualism under imperfect monitoring abstract we consider a two player prisoner s dilemma type game with continuous actions where players choose how much to contribute to a public project this game is played infinitely many times and actions are irreversible players cannot decrease their actions over time while it is strictly dominant for players not to contribute in the stage game some strictly positive level of contribution is pareto optimal it is known that when players perfectly observe each other s actions cooperation can be achieved through gradual increases in contribution levels i show that introducing an arbitrarily small amount of smooth noise in the monitoring makes cooperation impossible and players play the static nash equilibrium of the stage game forever