risk sharing and contagion in networks we investigate the socially optimal design of financial networks that allows to tackle the trade off between risk sharing and contagion we identify conditions on the shock distribution under which full integration or maximal segmentation is optimal we also show that under different conditions the optimal network displays different levels of strength of linkages to other firms or intermediate degrees of segmentation in the latter case the individual and social incentives to establish linkages are not necessarily aligned when firms face heterogeneous distributions of risks they should optimally form linkages only with firms facing risks of the same kind

systemic risk in financial systems a feedback approach abstract we develop an innovative framework to estimate systemic risk that accounts for feedback effects between the real and financial sectors we model the feedback effects through successive deterioration of borrowers creditworthiness and illiquidity spreading thus giving rise to a micro level financial accelerator between firms and banks we demonstrate that the model converges to a unique fixed point and the key role that centrality plays in shaping the level of amplification of shocks we also provide a mathematical framework to explain systemic risk variations in time as a function of the network characteristics of economic agents finally we supply empirical evidence on the economic significance of the feedback effects on comprehensive loan level data of the brazilian credit register our results corroborate the importance of incorporating new contagion channels besides the traditional interbank market in systemic risk models

network models and financial stability abstract systemic risk is a key concern for central banks charged with safeguarding overall financial stability in this paper we investigate how systemic risk is affected by the structure of the financial system we construct banking systems that are composed of a number of banks that are connected by interbank linkages we then vary the key parameters that define the structure of the financial system including its level of capitalisation the degree to which banks are connected the size of interbank exposures and the degree of concentration of the system and analyse the influence of these parameters on the likelihood of knock on defaults first we find that the better capitalised banks are the more resilient is the banking system against contagious defaults and this effect is non linear second the effect of the degree of connectivity is non monotonic i e initially a small increase in connectivity increases the contagion effect but after a certain threshold value connectivity improves the ability of a banking system to absorb shocks third the size of interbank liabilities tends to increase the risk of knock on default even if banks hold capital against such exposures fourth more concentrated banking systems are shown to be prone to larger systemic risk all else equal in an extension to the main analysis we study how liquidity effects interact with banking structure to produce a greater chance of systemic breakdown we finally consider how the risk of contagion might depend on the degree of asymmetry tiering inherent in the structure of the banking system a number of our results have important implications for public policy which this paper also draws out

interbank market liquidity and central bank intervention we develop a simple model of the interbank market where banks trade a long term safe asset when there is a lack of opportunities for banks to hedge idiosyncratic and aggregate liquidity shocks the interbank market is characterized by excessive price volatility in such a situation a central bank can implement the constrained efficient allocation by using open market operations to fix the short term interest rate it can be constrained efficient for banks to hoard liquidity and stop trading with each other if there is sufficient uncertainty about aggregate liquidity demand compared to idiosyncratic liquidity demand

financial globalization financial crises and contagion abstract two observations suggest that financial globalization played an important role in the recent financial crisis first more than half of the rise in net borrowing of the u s non financial sectors since the mid 1980s has been financed by foreign lending second the collapse of the u s housing and mortgage backed securities markets had worldwide effects on financial institutions and asset markets using an open economy model where financial intermediaries play a central role we show that financial integration leads to a sharp rise in net credit in the most financially developed country and to large asset price spillovers of country specific shocks to bank capital the impacts of these shocks on asset prices are amplified by bank capital requirements based on mark to market

the formation of networks with transfers among players we examine the formation of networks among a set of players whose payoffs depend on the structure of the network when players may bargain by promising or demanding transfer payments when forming links we vary three aspects of the game i whether players can only make transfers to and receive transfers from players to whom they are directly linked or whether they can also subsidize links that they are not directly involved in ii whether or not transfers relating to a given link can be made contingent on the full resulting network or only on the link itself and iii whether or not players can pay other players to refrain from forming links we characterize the networks that are supported under these variations and show how each of the above aspects either accounts for a specific type of externality or deals with the combinatorial nature of network payoffs

efficiency and sharing of investment in specific human capital under risk aversion abstract this paper analyses the investment behavior of a risk averse worker who searches for other jobs in a two period model it will be shown that given an appropriate investment technology the worker will invest in specific human capital efficiently if his investment costs and return can be shared with some parties the presence of sharing allows the worker to invest efficiently without being affected by his risk aversion since he can adjust his share of the investment in a way compatible with his attitude towards risk

capital markets the separation property and hedging abstract we consider a risk averse firm facing exchange rate and interest rate uncertainty when international capital markets are accessible the separation property holds however these hedging instruments are not equivalent to creating missing interest rate futures markets

the interbank market after august 2007 what has changed and why after the onset of the financial crisis spreads between interbank interest rates on unsecured and secured deposits for the major world currencies became exceptionally large and volatile first we find that the phenomenon was mainly driven by aggregate rather than bank specific factors notably risk aversion and accounting practices by contrast funding liquidity capital shortage and central bank interventions were not important determinants second prior to august 2007 the spread was broadly insensitive to key borrower characteristics whereas afterward it became somewhat more reactive to measures of creditworthiness third conditions for big borrowers became relatively more favorable during the crisis suggesting that moral hazard risks related to the too big to fail argument have increased these results are discussed in the light of theories on the interbank market during a crisis

contagion and risk sharing on the inter bank market abstract increasing inter bank lending has an ambiguous impact on financial stability using a computational model with endogenous bank behavior and interest rates we identify the conditions under which inter bank lending promotes stability through risk sharing or provides a channel through which failures may spread in response to large economy wide shocks more inter bank lending relationships worsen systemic events for smaller shocks the opposite effect is observed as such no inter bank market structure maximizes stability under all conditions in contrast deposit insurance costs are always reduced under greater numbers of inter bank lending relationships a range of regulations are considered to increase system stability

introducing new futures contracts reinforcement versus cannibalism abstract in order to assure survival futures exchanges around the world are in constant search of new futures contracts that will generate a profitable level of trading volume introducing new futures contracts may increase or decrease the volume for those contracts already listed using a multi product hedging model in which the perspective has been shifted from portfolio to exchange management we study these effects using data from two exchanges that differ regarding assets traded and market liquidity amsterdam exchanges versus chicago board of trade we show the usefulness of the proposed method the method may also be used to evaluate the benefits for exchanges that plan to internationalize their activities by merging with another exchange or by cross listing other exchanges futures contracts

identifying relationship lending in the interbank market a network approach abstract relationship lending is broadly interpreted as a strong partnership between a lender and a borrower nevertheless we still lack consensus regarding how to quantify the strength of a lending relationship while simple statistics such as the frequency and volume of loans have been used as proxies in previous studies here we propose statistical tests to identify relationship lending as a significant tie between banks application of the proposed method to the italian interbank networks reveals that the fraction of relationship lending among all bilateral trades has been quite stable and that the relationship lenders tend to impose high interest rates at the time of financial distress

trading in networks theory and experiments intermediation is a prominent feature of economic production and exchange two features of intermediation are salient coordination among traders between the source and the destination and competition between alternative combinations of intermediaries we develop a simple model to study these forces and we test the theoretical predictions in experiments our theoretical analysis yields a complete characterization of pricing equilibrium in networks there exist both ecient and inecient equilibria suggesting a key role of coordination among intermediaries strategic interaction leads to either buyer and seller retaining all surplus or intermediaries extracting all surplus we develop conditions on network structure under which these di erent extremal outcomes arise respectively laboratory experiments show that eciency prevails in almost all cases so traders are successful in coordination subjects coordinate on extreme surplus division finally experiments highlight the role of network structure in determining pricing and the

the behavior of the exchange rate in the genetic algorithm and experimental economies this paper studies the behavior of the exchange rate in the kareken wallace overlapping generations economy with two currencies in which decision rules are updated using the genetic algorithm the analysis shows that a stationary monetary equilibrium of the kareken wallace model is not stable under the genetic algorithm dynamics the fluctuations in the genetic algorithm exchange rate are driven by fluctuations in the portfolio fractions which change over time in response to the inequality between the rates of return on two currencies further both the genetic algorithm simulations and the experiments with human subjects were characterized by continuing fluctuations of the exchange rate with first period consumption values close to a stationary value

the intraday price of money evidence from the e mid interbank market we provide empirical evidence based on tick by tick data for the e mid euro area interbank market covering 2003 and 2004 that the overnight interest rate shows a clear downward pattern throughout the operating day thus a positive hourly interest rate half basis point implicitly emerges from the intraday term structure of the overnight rate such a pattern was not detected in the mid 1990s we explain this evolution as an outcome of the recent trend toward real time settlement the estimated intraday interest rate is lower than in the united states this is due to the different cost of central bank daylight credit

a network model of financial system resilience abstract we examine the role of macroeconomic fluctuations asset market liquidity and network structure in determining contagion and aggregate losses in a stylized financial system systemic instability is explored in a financial network comprising three distinct but interconnected sets of agents domestic banks overseas banks and firms calibrating the model to advanced country banking sector data this preliminarily model generates broadly sensible aggregate loss distributions which are bimodal in nature we demonstrate how systemic crises may occur and analyse how our results are influenced by firesale externalities and the feedback effects from curtailed lending in the macroeconomy we also illustrate the resilience of our model financial system to stress scenarios with sharply rising corporate default rates and falling asset prices

optimal hedging by firms with multiple sources of risky revenues abstract we study the hedging behavior of competitive risk averse firms producing under price uncertainty and owning other sources of risky income as well we show that the well known separation property holds when a futures market for the commodity produced is available however unbiased futures market does not imply full hedging by which the firm avoids price risk altogether

hedging with price and output uncertainty abstract this paper extends mckinnon s analysis of hedging with price and output uncertainty to the general case where preferences are not necessarily quadratic and probability distribution not necessarily normal

dynamics of networks if everyone strives for structural holes when entrepreneurs enter structural holes in networks they can exploit the related benefits evidence for these benefits has steadily accumulated the authors ask whether those who strive for such structural advantages can maintain them if others follow their example burt speculates that they cannot but a formal demonstration of this speculation is lacking using a game theoretic model of network formation the authors characterize the networks that emerge when everyone strives for structural holes they find that the predominant stable networks distribute benefits evenly confirming that no one is able to maintain a structural advantage in the long run

segregation in friendship networks we analyze a network formation model where agents belong to different communities both individual benefits and costs depend on direct as well as indirect connections benefits of an indirect connection decrease with distance in the network while the cost of a link depends on the type of agents involved two agents from the same community always face a low linking cost while the cost of forming a relationship between two agents from different communities diminishes with the rate of exposure of each of them to the other community we find that socialization among the same type of agent can be weak even if the cost of maintaining links within one s own type is very low our model also suggests that policies aimed at reducing segregation are socially desirable only if they reduce the within community cost differential by a sufficiently large amount

coalitional bargaining in networks we analyze a noncooperative bargaining game with a general coalition structure in each period an opportunity for a feasible coalition to form arises according to a stochastic process and a randomly selected agent in the coalition makes a take it or leave it offer to the other agents in the coalition we develop a new technique based on convex programming to characterize the unique stationary equilibrium payoff of the game we apply the framework to various settings including trading networks with middlemen and cooperation networks with overlapping communities in these applications feasible coalitions are determined by an underlying network structure we study the effect of the underlying network on the pattern of trade and show how an agent s payoff is related to her position in the network

an empirical study of the mexican banking system s network and its implications for systemic risk abstract with the aim to measure and monitor systemic risk we present some topological metrics for the interbank exposures and the payments system networks the evolution of such networks is analyzed we draw important conclusions from the systemic risk s perspective and propose a measure of interconnectedness additionally we suggest non topological measures to describe individual behavior of banks in both networks the main findings of this paper are the structures of the payments and exposures networks are different in terms of connectivity the topology of the exposures network changed after the collapse of lehman brothers whereas the structure of the payments network does not the proposed measure of interconnectedness can be used to determine the importance of a bank in terms of connectivity finally we found that interconnectedness of a bank is not necessarily related with its assets size but it is linked to the contagion it might cause

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

rules of thumb for social learning this paper studies agents who consider the experiences of their neighbors in deciding which of two technologies to use we analyze two learning environments one in which the same technology is optimal for all players and another in which each technology is better for some of them in both environments players use exogenously specified rules of thumb that ignore historical data but may incorporate a tendency to use the more popular technology in some cases these naive rules can lead to fairly efficient decisions in the long run but adjustment can be slow when a superior technology is first introduced

job information networks neighborhood effects and inequality this paper explores the theoretical and empirical literature to examine the use by different social groups of informal sources of information provided by friends relatives and acquaintances during job search and its consequences for the job market it also addresses the role of network structure and size the resource endowments of contacts and nature of the links between contacts to explain differences in the effects of job information networks in doing so the paper also turns to the sociology literature on job information networks and provides an economic perspective on such sociological concepts as strong versus weak ties inbreeding distance from structural holes etc the paper distinguishes between models of exogenous job information networks that is where individuals obtain job related information through a given social structure and endogenous job information networks which are social networks that result from individuals uncoordinated actions the paper pays special attention to such issues as physical and social proximity and sharing of information and discusses them in the context of the recent social interactions and neighborhood effects literature finally the paper outlines a model that integrates job information networks where interactions occur in business cycle frequencies with the dynamics of human capital formation which include the joint effects of parental community and neighborhood human capital and are set in life cycle frequencies for the purpose of organizing suggestions for future research and examining earned income inequality

a network analysis of the italian overnight money market the objective of this paper is to analyse the network topology of the italian segment of the european overnight money market through methods of statistical mechanics applied to complex networks we investigate differences in the activities of banks of different sizes and the evolution of their connectivity structure over the maintenance period the main purpose of the analysis is to establish the potential implications of the current institutional arrangements on the stability of the banking system and to assess the efficiency of the interbank market in terms of absence of speculative and preferential trading relationships

interest rate dispersion and volatility in the market for daily funds abstract the purpose of this paper is to study the determinants of equilibrium in the market for daily funds we use the eonia panel database which includes daily information on the lending rates applied by contributing commercial banks the data clearly show an increase in both the time series volatility and the cross section dispersion of rates towards the end of the reserve maintenance period these increases are highly correlated we design a model to account for these empirical facts our theoretical model shows how the operational framework of monetary policy causes a reduction in the elasticity of the supply of funds by banks throughout the reserve maintenance period this reduction in the elasticity together with market segmentation and heterogeneity is able to generate distributions for the interest rates and quantities traded with the same properties as in the data we also investigate the effects of the changes in the eurosystem s operational framework enacted on march 2004 for interest rate behaviour

r d networks we develop a model of strategic networks that captures two distinctive features of interfirm collaboration bilateral agreements and nonexclusive relationships our analysis highlights the relationship between market competition firms incentives to invest in r d and the architecture of collaboration networks in the absence of firm rivalry the complete network where each firm collaborates with all others is uniquely stable industry profit maximizing and efficient by contrast under strong market rivalry the complete network is stable but intermediate levels of collaboration and asymmetric networks are more attractive from a collective viewpoint this suggests that competing firms may have excessive incentives to form collaborative links

the large small bank dichotomy in the federal funds market abstract despite the central importance of the federal fund market little research has been undertaken on the micro decision making of individual market participants and their interactions this paper demonstrates that there are asymmetries of information between federal funds lenders and borrowers that can only be resolved through frequent and continuous trading smaller banks are constrained in their ability to borrow federal funds due to their size and location it is shown that information asymmetries and resulting adverse selection problems may be resolved through the use of implicit multi period contracts

reconstructing and stress testing credit networks abstract financial networks are an important source of systemic risk but often only partial network information is available in this paper we use data on bank firm credit relationships in japan and conduct a horse race between different network reconstruction methods in terms of their ability to reproduce the actual credit networks we then compare the different reconstruction methods in terms of their implied levels of systemic risk based on a standard model of price mediated contagion we find that the observed credit network displays relatively high levels of systemic risk compared with most reconstruction methods lastly we explore whether different policies can improve the robustness of the system

a model of financial fragility abstract this article presents a dynamic stochastic game theoretic model with two essential features first agents hold diversified portfolios that link their financial positions to those of other agents second shocks to fundamentals at the initial date cause some portfolio losses agents who incur losses reallocate their portfolios thereby breaking some linkages in the pareto efficient symmetric equilibrium studied two related types of financial crisis can occur in response one occurs gradually as losses spread breaking more links the other type occurs instantaneously when forward looking agents preemptively shift to safer portfolios to avoid future losses from contagion an economy is more fragile the earlier its last remaining link breaks from such a crisis journal of economic literature classification numbers c7 e00 e3 e44 g1

systemic risk financial contagion and financial fragility abstract although it is hard to arrive at a widely accepted definition for systemic risk it is generally acknowledged that it is the risk of the occurrence of an event that threatens the well functioning of the system of interest financial payments banking etc sometimes to the point of making its operation impossible we model systemic risk with two main components a random shock that weakens one or more financial institutions and a transmission mechanism which transmits and possibly exacerbates such negative effects to the rest of the system our model could be conceptually represented by a network already described in previous works in this work we show how is possible to estimate the distribution of losses for the banking system with our model additionally we show how it is possible to separate the distribution of losses into two components the losses incurred by the initial shock and the losses resulting from the contagion process finally once the distribution is estimated we can derive standard risk measures for the system as a whole another important contribution of this work is that we can follow the evolution of certain risk measures like the expected loss or the cvar in order to evaluate if the system is becoming more or less risky in fact more or less fragile additionally we can decompose the distribution of losses of the whole banking system into the systemic and the contagion elements and we can determine if the system is more prone to experience contagious difficulties during a certain period of time

the effect of the interbank network structure on contagion and common shocks abstract this paper proposes a dynamic multi agent model of a banking system with central bank banks optimize a portfolio of risky investments and riskless excess reserves according to their risk return and liquidity preferences they are linked via interbank loans and face stochastic deposit supply comparing different interbank network structures it is shown that money centre networks are more stable than random networks evidence is provided that the central bank stabilizes interbank markets in the short run only systemic risk via contagion is compared with common shocks and it is shown that both forms of systemic risk require different optimal policy responses

the role of bank relationships in the interbank market this paper empirically explores the effect of bank lending relationships in the interbank market we use data from the e mid market that represents the only transparent electronic platform in europe and usa unaffected by search costs and other fictions we show that stable relationships exist and that they played a significant role during the 2007 2008 financial crisis trading with preferred counterparts is associated with more favorable rates for both lenders and borrowers and carries larger trading volumes the results point to a peer monitoring role of relationship lending which contributes at a time of financial distress to a smooth liquidity redistribution among banks relationship lending thus plays an important positive role for financial stability

international trade with forward futures markets under exchange rate and price uncertainty abstract the paper examines a risk averse firm s decisions on the level of trade when the exchange rate and the commodity price are uncertain and the extent of forward exchange and commodity futures commitments first we verify the separation theorem and the full double hedging theorem second we investigate the implications of the existence of both forward foreign exchange and commodity futures markets in comparison to the case where only one or no market is available to the firm the second exercise enables us to focus on conditions under which establishing forward futures arrangements promotes international trade

liaisons dangereuses increasing connectivity risk sharing and systemic risk the recent financial crisis poses the challenge to understand how systemic risk arises endogenously and what architecture can make the financial system more resilient to global crises this paper shows that a financial network can be most resilient for intermediate levels of risk diversification and not when this is maximal as generally thought so far this finding holds in the presence of the financial accelerator i e when negative variations in the financial robustness of an agent tend to persist in time because they have adverse effects on the agent s subsequent performance through the reaction of the agent s counterparties 2012 elsevier b v all rights reserved

trade expansion and contract enforcement consider a world of traders separated in geographic economic or social space honest trade offers larger gains for more distant traders but frequencies of meetings and information flows about cheating have local bias honesty is self enforcing only between pairs of sufficiently close neighbors global honesty prevails only in a sufficiently small world the extent of self enforcing honesty is likely to decrease when the world expands beyond this size costly external enforcement is useful only if the world is sufficiently large and its net payoff need not be larger than that of a self governing small community intermediate size worlds fare worst

exporting firm and forward markets the multiperiod case abstract we consider a model with a competitive risk averse exporting firm who faces uncertain exchanges rates in a multiperiod analysis the capital stock or fixed input has to be determined at the outset while the variable input labor is chosen optimally at the beginning of each period but before the realization of the exchange rate we show that introducing unbiased currency forward markets decreases the capital labor ratio in all periods we also show that such a firm tends to overhedge compared to the one period cases in some cases the introduction of unbiased forward markets results in higher investments and production in all dates

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

financial regulations and bank credit to the real economy we present a new agent based model focusing on the linkage between the interbank market and the real economy with a stylised central bank acting as lender of last resort using this model we address the tradeoff between stability and economic performance for different structures of the interbank market we also explore the efficacy of recent regulatory reforms using our richer model our results suggest that the effects of regulatory leverage ratios on the banking sector s performance can vary in a complex and non monotonic way with the state of the economy the degree of connectivity of the interbank market and the amount of information available to market participants on bank risks

organizational capabilities and the economic history of the industrial enterprise in my book scale and scope 1990 i focused on the history of the modern industrial firm from the 1880s when such firms first appeared through world war ii i did so by comparing the fortunes of more than 600 enterprises the 200 largest industrial firms at three points in time world war i 1929 and world war ii in each of the three major industrial economies those of the united states britain and germany in this paper i first describe the similarities in the historical beginnings and continuing evolution of these enterprises and then outline my explanation for these similarities next i relate my explanation of these empirical regularities to four major economic theories relating to the firm the neoclassical the principal agent the transaction cost and the evolutionary finally i suggest the value of the transactions cost and evolutionary theories to historians and economists who are attempting to explain the beginnings and growth of modern industrial enterprises

social networking and individual outcomes beyond the mean field case we study individually optimized continuous outcomes in a dynamic environment in the presence of social interactions and where the interaction topology may be either exogenous and time varying or endogenous the model accommodates more general social effects than those of the mean field type we address endogenous networking by assuming that each individual chooses the weights she attaches to the characteristics and the decisions of other agents this amounts to choosing the elements of a row of a weighted adjacency matrix endogenous social networking thus involves simultaneity between decisions and patterns of directed social interactions

structural holes in social networks we consider a setting where every pair of players that undertake a transaction e g exchange goods or information creates a unit surplus a transaction can take place only if the players involved have a connection if the connection is direct the two players split the surplus equally while if it is indirect then intermediate players also get an equal share of the surplus thus individuals form links with others to create surplus to gain intermediation rents and to circumvent others who are trying to become intermediary our analysis clarifies the interplay between these forces in the process of strategic network formation first we show that in the absence of capacity constraints on links it leads to the emergence of a star network where a single agent acts as an intermediary for all transactions and enjoys significantly higher payoffs second we study the implications of capacity constraints in the ability of agents to form links in this case distances between players must be long which induces players who are far off to connect in order to avoid paying large intermediation rents a cycle network then emerges payoffs being equal across all players

systemic risk in the netting system abstract in interbank clearing networks a bank experiencing sudden liquidity or solvency problems may prevent settlement of the claims of its direct creditors which may in turn jeopardize settlement of other institutions the paper presents an empirical assessment of the potential size of this domino effect in the italian netting system a participant s settlement failure is simulated and the impact on the rest of the system measured on average only about 4 percent of participants were large enough to trigger systemic crises less than 1 percent defaulted due to systemic reasons the average monetary loss was less than 3 percent of the daily flow of funds through the clearing system similar simulations by other authors for the u s system yielded a much larger impact of systemic risk we argue that the difference is mainly due to the much smaller volume of funds flowing through the italian system and to structural differences

liquidity coinsurance moral hazard and financial contagion we study the propagation of financial crises between regions characterized by moral hazard problems the source of the problem is that banks are protected by limited liability and may engage in excessive risk taking the regions are affected by negatively correlated liquidity shocks so that liquidity coinsurance is pareto improving the moral hazard problem can be solved if banks are sufficiently capitalized under autarky a limited investment is needed to achieve optimality so that a limited amount of capital is sufficient to prevent risk taking with interbank deposits the optimal investment increases and capital becomes insufficient to prevent excessive risk taking thus bankruptcy occurs with positive probability and the crises spread to other regions via the financial linkages opening the financial markets is nevertheless pareto improving consumers benefit from liquidity coinsurance although they pay the cost of excessive risk taking finally we show that in this framework a completely connected deposit structure is more conducive to financial crises than an incompletely connected structure

banks as monitors of other banks evidence from the overnight federal funds market this study provides evidence that banks are effective monitors of their peers by showing that the interest rate paid on federal funds transactions reflects differences in credit risk across borrowers in addition the size and relative importance in the funds market of the trading institutions are shown to affect the rates charged for overnight borrowing thereby providing insight into the nature of competition in the federal funds market transaction volume and size of transaction effects are uncovered as is evidence of relationship banking between banks these results are made possible by unique data identifying individual federal funds transactions copyright 2001 by university of chicago press

imperfect hedging and export production firms engaged in international operations are highly interested in developing ways to protect themselves from exchange rate risk the incentive for risk management comes from the enormous volatility of the floating foreign exchange rates our study shows that an exporting firm can benefit from hedging exchange rate risks even when no perfect hedge is possible since in reality not every currency is traded in a futures market 7 chap 15 the exporting firm uses futures contracts with other underlying assets whose spot prices are highly correlated with the foreign exchange spot rate in the real world hedging must often be accomplished by using futures contracts on different deliverable instruments such hedging may result in imperfect hedging as shown by anderson and danthine 1 eaker and grant 11 dellas and zilberfarb 9 broll wahl and zilcha 6 it has been shown in recent publications 12 8 15 13 23 16 2 14 5 18 22 that an international firm facing exchange rate risk can eliminate this risk altogether if it can use a currency forward market another financial asset or a portfolio of assets which is perfectly correlated to the exchange rate in the absence of such markets the firm can reduce its income risk by engaging in a hedging activity of assets correlated to the foreign exchange recent studies of firm behavior under exchange rate uncertainty examine the influence of futures markets on the export and hedging decision these papers derive two major theorems one is the separation theorem which states that when futures markets exist the firm s export production decision is determined solely by technology and input output prices including the futures prices this result holds if the gain from the futures contract is perfectly correlated with export revenue the other theorem is the full hedging theorem which asserts that with unbiased futures markets the firm completely avoids exchange rate risk by entering into optimum futures contracts

a strategic model of social and economic networks we study the stability and efficiency of social and economic networks when self interested individuals can form or sever links first for two stylized models we characterize the stable and efficient networks there does not always exist a stable network that is efficient next we show that this tension persists generally to assure that there exists a stable network that is efficient one is forced to allocate resources to nodes that are not responsible for any of the production we characterize one such allocation rule the equal split rule and another rule that arises naturally from bargaining of the players

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

structural holes in social networks a remark abstract in a recent article s goyal f vega redondo structural holes in social networks j econ theory 137 1 2007 460 492 the authors gvr showed the importance of stars and cycles in a given network formation game implicitly in their article a network is called an equilibrium if it is generated by an equilibrium strategy we extend the results of gvr to the case of a stronger requirement namely that a network can be called an equilibrium only if all the strategies generating it are equilibria we also show in a dynamic framework that both definitions differ in crucial ways

farsighted network formation this paper studies a model of dynamic network formation when individuals are farsighted players evaluate the desirability of a current move in terms of its consequences on the entire discounted stream of payoffs we define a concept of equilibrium which takes into account farsighted behavior of agents and allows for limited cooperation amongst agents we show that an equilibrium process of network formation exists we also show that there are valuation structures in which no equilibrium strategy profile can sustain efficient networks we then provide sufficient conditions under which the equilibrium process will yield efficient outcomes

movers and shakers most projects in most walks of life require the participation of multiple parties while it is difficult to unite individuals in a common endeavor some people who we call movers and shakers seem able to do it the paper specifically examines moving and shaking of an investment project whose return depends both on its quality and the total capital invested in it we analyze a model with two types of agents managers and investors managers and investors initially form social connections managers then bid to buy control of the project and the winning bidder puts effort into making investors aware of it finally a subset of aware investors are given the chance to invest and they decide whether to do so after receiving private signals of the project s quality we first show that connections are valuable since they make it easier for a manager to move and shake the project i e obtain capital from investors when we endogenize the network we find that while managers are identical ex ante a single manager emerges as most connected he consequently earns a rent in extensions we move away from the assumption of ex ante identical managers to highlight forces that lead one manager or another to become a mover and shaker our theory sheds light on a range of topics including entrepreneurship venture capital and anchor investments

financial networks contagion commitment and private sector bailouts i develop a model of financial networks in which linkages not only spread contagion but also induce private sector bailouts where liquid banks bail out illiquid banks because of the threat of contagion introducing this bailout possibility i show that linkages may be optimal ex ante because they allow banks to obtain some mutual insurance even though formal commitments are impossible however in some cases e g when liquidity is concentrated among a small group of banks the whole network may collapse i also characterize the optimal network size and apply the results to joint liability arrangements and payment systems linkages among agents in financial markets are a concern because of the risk of financial contagion that is the risk that a small shock to one agent will spread to other agents in a domino effect whether we should worry about these linkages is an open question the main goal of this paper is to show that a network in which agents are closely interlinked may be optimal both because of and despite the potential for contagion another goal is to characterize optimal networks that is whether and how agents should be linked to one another the basic intuition is as follows linkages present the threat of contagion to prevent collapse of the whole network agents who are lucky ex post may be willing to bail out those who are not in this way agents obtain the benefits of mutual insurance even though they cannot precommit to making payments

corporate financing an artificial agent based analysis we examine corporate security choice by simulating an economy populated by adaptive agents who learn about the structure of security returns and prices through experience through a process of evolutionary selection each agent gravitates toward strategies that generate the highest payoffs despite the fact that markets are perfect and agents maximize value a financing hierarchy emerges in which straight debt dominates other financing choices equity and convertible debt display significant underpricing in general the smaller the probability of loss to outside investors the more likely the firm is to issue the security and the smaller the security s underpricing

export and hedging decisions under revenue and exchange rate risk a note abstract this note analyzes optimal export and hedging decisions taken by a risk averse exporting firm which simultaneously faces hedgeable exchange rate risk and non hedgeable revenue risk abroad the separation property does not hold exports depend on preferences and expectations revenue uncertainty causes the firm to export less the optimal currency forward position can be divided into three components an expected revenue component a speculative component and a revenue uncertainty component

bank failure contagion in historical perspective abstract bank failures are contagious due to the lack of bank specific information depositors who lack financial information on individual banks make withdrawal decisions based on the condition of the banking system as a whole a high ratio of bank failures then signals an adverse condition within the banking sector and triggers systemwide bank runs this paper looks at bank panics in u s history and shows the importance of solvency information specific to individual banks the major empirical finding is that the government or banks stopped bank panics mainly by providing financial information on banks

systemic risk in financial systems we consider default by firms that are part of a single clearing mechanism the obligations of all firms within the system are determined simultaneously in a fashion consistent with the priority of debt claims and the limited liability of equity we first show via a fixed point argument that there always exists a clearing payment vector that clears the obligations of the members of the clearing system under mild regularity conditions this clearing vector is unique next we develop an algorithm that both clears the financial system in a computationally efficient fashion and provides information on the systemic risk faced by the individual system firms finally we produce qualitative comparative statics for financial systems these comparative statics imply that in contrast to single firm results even unsystematic nondissipative shocks to the system will lower the total value of the system and may lower the value of the equity of some of the individual system firms

the organisational factor and the growth of firms the paper analyses the role played by the managerial factor in conditioning the rhythm and intensity of firms growth it argues that growth has to be intended as a measure of the capability of the firm to successfully cope with the problems arising from increasing complexity according to a penrosean perspective such a capability may be bounded at any given time by a lack of those internal managerial resources which provide the firm with a set of uniquely valuable services and which create a differential advantage over its competitors in a dynamic capabilities view such advantages need to be continuously modified through a process of search and selection this has assumed peculiar relevance in the face of the hyper competition regime characterising the more recent phase of industrial development asking firms executives to develop an increasing ability to find creative solutions to continuously moving targets therefore making the management function a key driver to change

growing stars a laboratory analysis of network formation abstract efficient information dispersion occurs with star networks where small numbers of agents gather information for distribution to larger groups previous studies have shown that ex ante heterogeneity in payoff incentives among agents is sufficient for reliable star formation goeree et al 2009 using laboratory experiments we show stars reliably emerge among ex ante homogeneous agents under specific institutional environments our results help to explain why star networks emerge frequently among homogeneous groups particularly rural farming communities conley and udry 2010 our findings have implications for developing countries where it is crucial to create mechanisms to promote efficient information sharing

the benefits of lending relationships evidence from small business data this paper empirically examines how ties between a firm and its creditors affect the availability and cost of funds to the firm we analyze data collected in a survey of small firms by the small business administration the primary benefit of building close ties with an institutional creditor is that the availability of financing increases we find smaller effects on the price of credit attempts to widen the circle of relationships by borrowing from multiple lenders increases the price and reduces the availability of credit in sum relationships are valuable and appear to operate more through quantities rather than prices

credit contagion and aggregate losses abstract credit contagion refers to the propagation of economic distress from one firm to another this article proposes a reduced form model for these contagion phenomena assuming they are due to the local interaction of firms in a business partner network we study aggregate credit losses on large portfolios of financial positions contracted with firms subject to credit contagion in particular we provide an explicit gaussian approximation of the distribution of portfolio losses this enables us to quantify the relation between the volatility of losses and the determinants of credit contagion we find that contagion processes have typically a second order effect on portfolio losses they induce additional fluctuations of losses around their averages whose size depends on the number of business partners of the firms

credit risk in a network economy we develop a structural model of credit risk in a network economy where any firm can lend to any other firm so that each firm is subject to counterparty risk either from direct borrowers or from remote firms in the network this model takes into account the role of each firm s cash management we show that we can obtain a semiclosed form formula for the price of debt and equity when cash accounts are buffers to bankruptcy risk as in other structural models the strategic bankruptcy decision of shareholders drives credit spreads and differentiates debt from equity cash flow risk also causes credit risk interdependencies between firms our model applies to the case where not only financial flows but also operations are dependent across firms we use queueing theory to obtain our semiclosed form formulae in steady state we perform a simplified implementation of our model to the u s automotive industry and show how we infer the impact on a supplier s credit spreads of revenue changes in a manufacturer or even in a large car dealer we also obtain prices for first to default and second to default basket credit default swaps

the formation of a core periphery structure in heterogeneous financial networks recent empirical evidence suggests that nancial networks exhibit a core periphery network structure this paper aims at giving an economic explanation for the emergence of such a structure using network formation theory focusing on intermediation benets we nd that a core periphery network cannot be unilaterally stable when agents are homogeneous the best response dynamics converge to a unique unilaterally stable outcome ranging from an empty to denser networks as the costs of linking decrease a core periphery network structure can form endogenously however if we allow for heterogeneity among agents in size we show that our model can reproduce the observed core periphery structure in the dutch interbank market for reasonable parameter values

interbank contagion at work evidence from a natural experiment this article tests financial contagion due to interbank linkages for identification we exploit an idiosyncratic sudden shock caused by a large bank failure in conjunction with detailed data on interbank exposures first we find robust evidence that higher interbank exposure to the failed bank leads to large deposit withdrawals second the magnitude of contagion is higher for banks with weaker fundamentals third interbank linkages among surviving banks further propagate the shock finally we find results suggesting that there are real economic effects these results suggest that interbank linkages act as an important channel of contagion and hold important policy implications jel g01 g21 g28 e58 since the onset of the financial turmoil increased uncertainty reflected particularly in counterparty risk has led banks to hoard liquidity this has resulted in a significant decline of trading in the interbank money markets jean claude trichet president of the european central bank december 2008

conformism and self selection in social networks i present a model of conformism in social networks that incorporates both peer effects and self selection i show that conformism has positive social value and that social welfare can be bounded by network polarization and connectivity measures i apply the model to empirical data on high school students participation in extracurricular activities i find that the local effect of conformism i e the endogenous peer effect for a fixed network structure ranges from 7 5 to 45 depending on the number of peers that an individual has simulations show that the optimal policies of an inequality averse policymaker change depending on a school s enrollment small schools should encourage shy students to interact more with other students while large schools should focus on promoting role models within the school

networked relationships in the e mid interbank market a trading model with memory interbank markets are fundamental for bank liquidity management in this paper we introduce a model of interbank trading with memory our model reproduces features of preferential trading patterns in the e mid market recently empirically observed through the method of statistically validated networks the memory mechanism is used to introduce a proxy of trust in the model the key idea is that a lender having lent many times to a borrower in the past is more likely to lend to that borrower again in the future than to other borrowers with which the lender has never or has in frequently interacted the core of the model depends on only one parameter representing the initial attractiveness of all the banks as borrowers model outcomes and real data are compared through a variety of measures that describe the structure and properties of trading networks including number of statistically validated links bidirectional links and 3 motifs refinements of the pairing method are also proposed in order to capture finite memory and reciprocity in the model the model is implemented within the mason framework in java

the formation of financial networks modern banking systems are highly interconnected despite various benefits linkages between banks carry the risk of contagion in this article i investigate whether banks can commit ex ante to mutually insure each other when there is contagion risk in the financial system i model banks decisions to share this risk through bilateral agreements a financial network that allows losses to be shared among various counterparties arises endogenously i characterize the probability of systemic risk defined as the event that contagion occurs conditional on one bank failing in equilibrium interbank networks i show that there exist equilibria in which contagion does not occur