Existence of Nash networks in one-way flow models

This paper addresses the existence of Nash equilibria in one-way flow models in a number of different settings. In these models players form costly links with other players and obtain resources from them through the directed path connecting them. We find that heterogeneity in the costs of establishing links plays a crucial role for the existence of Nash networks. The paper also provides conditions for the existence of Nash networks in models where costs and values of links are heterogeneous. We would like to thank an anonymous referee for useful suggestions. We would also like to thank Hans Haller and participants at the AEA Meetings 2007 for helpful comments. Sudipta Sarangi acknowledges the support of NSF grant HSD-0527315 and the hospitality of CREUSET, Jean Monnet University.     

Market and underground activities in a two-sector dynamic equilibrium model

Summary. In this paper a two sector dynamic general equilibrium model is developed in order to evaluate the implications of the underground economy from a business cycle perspective. There are three main results. First, introducing an underground sector improves the fit of the model to the data, especially along several important labor market dimensions. Second, the model produces substantial internal propagation of temporary shocks. Third, it is shown that underground activities offer risk sharing opportunities by allowing households to smooth income through a proper labor allocation between the two sectors.Received: 17 June 2002, Revised: 25 April 2003, JEL Classification Numbers: E320, E260, J22, H200.We have benefited from the comments and suggestions of John Donaldson. We would also like to thank Paolo Siconolfi, Jean Pierre Danthine, Fausto Gozzi, Edmund Phelps, Gustavo Piga, Domenico Tosato, and the participants in the seminars at various universities, David Giles and Stefano Pisani for providing useful information on the underground data, Francesca Caponi for the comments and the information concerning the legal and fiscal aspects involved in the calibration, and Glenn Williams for the research assistance. Finally, we thank two anonymous referees for helpful comments on this and on earlier versions of the paper. Chiarini acknowledges financial support from the Ateneo Research fund of the University of Rome, La Sapienza, Dinamiche dell'integrazione europea e scelta di politica economica. All errors are ours. Correspondence to: F. Busato     

The flow through of cost changes in competitive telecommunications: Theory and evidence

Flow through refers to the effect of a change in incremental production costs on the prices of goods or services, and is a topic of great interest to regulators and others. This article provides a framework for both analyzing flow through, and for evaluating whether or not flow through, properly defined, occurs in the long distance telecommunications industry. We focus on the effects of changes in switched access charges on domestic long distance prices for the largest U.S. long distance carriers in the late 1990s. Utilizing a double bootstrap technique uniquely suited to this problem, we find flow through occurred over the sample period. The technique illustrated here may find useful applications in other regulated sectors.First version received: March 2003 / Final version received: January 2004The authors are grateful to the editor and two anonymous referees for helpful comments and suggestions. All remaining errors are the responsibility of the authors.     

Network topology and the efficiency of equilibrium

Different kinds of networks, such as transportation, communication, computer, and supply networks, are susceptible to similar kinds of inefficiencies. These arise when congestion externalities make the cost for each user depend on the other users' choice of routes. If each user chooses the least expensive (e.g., the fastest) route from the users' common point of origin to the common destination, the result may be Pareto inefficient in that an alternative choice of routes would reduce the costs for all users. Braess's paradox represents an extreme kind of inefficiency, in which the equilibrium costs may be reduced by raising the cost curves. As this paper shows, this paradox occurs in an (undirected) two-terminal network if and only if it is not series-parallel. More generally, Pareto inefficient equilibria occur in a network if and only if one of three simple networks is embedded in it.     

Imperfect common knowledge and the information value of prices

Summary. When economic agents have diverse private information on the fundamentals of the economy, prices may serve as a poor aggregator of this private information. We examine the information value of prices in a monopolistic competition setting that has become standard in the New Keynesian macroeconomics literature. We show that public information has a disproportionate effect on agents’ decisions, crowds out private information, and thereby has the potential to degrade the information value of prices. This effect is strongest in an economy with keen price competition. Monetary policy must rely on less informative signals of the underlying cost conditions.Received: 6 November 2003, Revised: 19 November 2004 JEL Classification Numbers: E31, E32, E58.This paper supersedes the discussion in the first half of our longer paper that circulated under the title “Public and Private Information in Monetary Policy Models”. We thank Andy Filardo, Marvin Goodfriend, Nobu Kiyotaki, John Moore, Stephen Morris and Lars Svensson for advice and comments at various stages of the project, and to Herakles Polemarchakis, Roko Aliprantis and an anonymous referee for their helpful comments and guidance. The views are those of the authors and do not necessarily represent those of the BIS. The second author acknowledges support from the U.K. ESRC under grant RES 000220450. Correspondence to: H.S. Shin     

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.     

The supply of education quality in a spatial model with asymmetric moving costs

The paper analyses the characteristics of the supply of higher education in different geographical macroareas using a strategic interaction framework. It focuses on universities operating in centralised funding system that autonomously set the quality of education showing that in equilibrium it is inversely related to students’ moving costs across areas. We show that in the presence of asymmetric information about workers’ ability and asymmetric costs of moving, the only PBE consistent with forward induction involves that only high ability workers acquire education and the quality of education is lower in macroareas where the moving costs are higher. Our model predicts that in economies with centralised university funding, educational policies must be regulated according to the specific socioeconomic characteristics of the area. Direct subsidies to universities may be ineffective in improving the quality of education in the less developed areas. When regional disparities are not too big, efficiency gains may be obtained by reducing moving costs.     

TALKING,SEARCHING, AND PRICING*

I study the implications of interpersonal communication for incentives for consumers to acquire information and firms’ pricing behavior. Firms market a homogeneous product and choose its price; consumers acquire price information at some cost to themselves. Also, each consumer accesses the information acquired by a sample of other consumers—interpersonal communication. An exogenous increase in the level of interpersonal communication decreases the information that consumers acquire, and, when search costs are low, firms price less aggressively. In an extension, consumers may choose to invest in interpersonal communication at some cost. A decrease in the costs of interpersonal communication decreases firms’ competition.     

Trust in triads: effects of exit, control, and learning

This paper provides theoretical background for some effects of social networks on trust. We study the implications of a model with rational actors in two settings with three actors. In the first setting, there are two trustees who are involved in transactions with one truster implying that the truster has an exit option. In the second setting, two trusters play with one trustee, which gives the trusters options for voice, i.e., complaining and informing each other about the trustee's behavior. We compare these models with a baseline model in which there is only one truster and one trustee. It turns out that the opportunities for placing and honoring trust do not change for the exit model compared to the baseline model. The opportunities for trust in the voice model differ from the baseline model only if both trusters inform each other at a rate that is high enough. Only if the possibilities for receiving information and transmitting information are large enough for both trusters, trust will increase due to the information exchange possibilities in the voice model.     

Governance structures in R&D networks: An analysis in the European context

This paper analyses governance structures used to organize partnerships in R&D networks using two approaches: transaction costs theory and social capital theory. We argue that these theories are complementary; this explains forms of governance through the degrees of administrative (structural and safeguard mechanism) and social factors (cohesion and openness) they embody. Data was obtained from European R&D networks created through Framework Programmes which include a great number of universities, non profit institutions and firms. Findings show the variables that characterize and explain the governance forms based on the applicability of R&D networks. This study not only provides a theoretical model for analysing governance structures of these networks, but is also useful for both improving the management of networks and for fostering collaboration at an international level.     

WATER QUALITY TRADING IN THE PRESENCE OF ABATEMENT‐COST SHARING

This paper examines how water quality trading interacts with nonpoint‐source abatement‐cost sharing (e.g., as currently practiced by the National Resource Conservation Service through its Environmental Quality Incentives Program [EQIP]) to promote the participation of nonpoint sources in a water quality market, participation that has thus far been noticeably lacking nationwide. As such, an idealized version of water quality trading is envisioned, where water quality trading and nonpoint cost sharing are treated as complementary policy instruments rather than substitutes. Toward this end, the subgame‐perfect equilibrium concept is used to model a “multilateral contracting” relationship between the regulatory authority and nonpoint sources when the regulator has incomplete information about the nonpoint sources' production costs. We characterize ex ante (or second‐best) nonpoint abatement levels when the regulator chooses cost‐share rates in concert with a water quality market. Numerical analysis indicates that current EQIP cost‐share rates would likely be lower and more flexibly determined in the presence of water quality trading. (JEL Q53)     

A new solution to the problem of adjudicating conflicting claims

Summary. For the problem of adjudicating conflicting claims, we consider the requirement that each agent should receive at least 1/n his claim truncated at the amount to divide, where n is the number of claimants (Moreno-Ternero and Villar, 2004a). We identify two families of rules satisfying this bound. We then formulate the requirement that for each problem, the awards vector should be obtainable in two equivalent ways, (i) directly or (ii) in two steps, first assigning to each claimant his lower bound and then applying the rule to the appropriately revised problem. We show that there is only one rule satisfying this requirement. We name it the “ rule”, as it is obtained by a recursion. We then undertake a systematic investigation of the properties of the rule.Received: 7 September 2004, Revised: 21 April 2005, JEL Classification Numbers: C79, D63, D74.William Thomson: Correspondence toWe thank Christopher Chambers, Youngsub Chun, Tarík Kara, Çağatay Kayí, Juan Moreno-Ternero, Toyotaka Sakai, and Michel Truchon for their comments. We also thank a referee for useful comments. This paper was presented at Columbia University, CORE, Bilkent University, Sabancí University, Université Laval, and Caltech, and at the Mallorca Review of Economic Design meeting. Thomson acknowledges support from the NSF under grant SES-0214691.     

Condorcet Jury Theorem or Rational Ignorance

We analyze a symmetric model of an election in which voters are uncertain about which of two alternatives is desirable for them. Each voter must incur some cost to acquire information about the alternatives. We show that by focusing on unbiased voting strategies, general symmetric signal structures can be degenerated to a two‐signal model. In addition, we show that for any sequence of unbiased voting equilibria, if the second‐order derivative of the information cost function at no information is zero, then the probability of electing the desirable alternative converges to one, that is, the Condorcet Jury Theorem is valid. Otherwise, this probability converges to some value less than one; that is, the “rational ignorance” hypothesis is valid.     

Rawlsian pricing of access to public facilities: A unidimensional illustration

We consider a setting where citizens using a public facility face an idiosyncratic private access cost and must also contribute to the costs of facility. We show that if the population is uniformly spread over the real line, the cost of a facility is independent of location and access costs are linear in distance, the Rawlsian access pricing is the unique cost sharing solution that satisfies the “core property” of secession-proofness. The latter amounts to the voluntary participation principle under which no group of citizens should be charged more than the cost incurred if it had acted on its own.     

Endogenous monetary policy and the liquidity effect

We compare the transmission mechanism of exogenous and endogenous monetary policies in a calibrated small open economy model with nominal and real rigidities. Under an exogenous monetary policy rule it takes implausible values of the intertemporal elasticity of substitution and the price adjustment costs to generate the liquidity and overshooting effects. Endogenous rules with strong feedback to inflation and output help to reproduce the response of the nominal interest and exchange rates to unanticipated monetary policy shocks that characterize the transmission mechanism of standard sticky price models. The liquidty and overshooting effects are always obtained when the model is augmented with a Taylor interest rate rule.JEL Classification: E32, E43Javier Andrés acknowledges support of CICYT grant SEC2002-0026. We thank the comments of two anonymous referees and the editor, Jordi Caballé, to an earlier version of the paper. The views expressed here are those of the authors and do not represent the view of the Banco de España.     

Virtual integration and endogenous growth in the world economy

This study develops a three-country model of endogenous growth that captures the role of the interconnection of country-specific communications networks (i.e., virtual integration), which affects the productivity of R&D activity through an increase in stock of knowledge capital. The number of countries connected to internationally interconnected networks is found to determine the structure of dynamic comparative advantages. That is, countries with interconnected networks have a dynamic comparative advantage in differentiated products that require communication and activities. In the connected countries, researchers gain from efficient activity through the utilization of the greater stock of knowledge capital. The author acknowledges the comments from the participants at the 56th International Atlantic Economic Conference, held October 16–19, 2003, in Quebec City, Canada. The author is also grateful to the anonymous referee of this journal for helpful comments and suggestions.     

Deconstructing gravity: trade costs and extensive and intensive margins

Abstract This paper uses data on US exports to decompose exports into the number of exporting firms (the extensive margin) and average export sales (the intensive margin). We show how a range of proxies for trade costs has different impacts on the two margins. Distance has a negative effect on both margins, but the magnitude is considerably larger for the extensive margin. Most of the variables capturing language, internal geography, infrastructure and import cost barriers work through the extensive margin. We show that these results are consistent with a Melitz‐style model of trade with heterogeneous firm productivity and fixed costs.     

Why banks should keep secrets

Summary. We show that it is sometimes efficient for a bank to commit to a policy that keeps information about its risky assets private. Our model, based upon Diamond-Dybvig (1983), has the feature that banks acquire information about their risky assets before depositors acquire it. A bank has the option of using contracts where the middle-period return on deposits is contingent on this information, but by doing so it must also reveal the information. We derive the conditions on depositors preferences and banking technology for which a bank would prefer to keep information secret even though it must then use a non-contingent deposit contract.Received: 5 November 2002, Revised: 19 December 2004, JEL Classification Numbers: D8, G21, G28.I would like to thank an anonymous referee, Sudipto Bhattacharya, Ed Green, Chandra Kanodia, Andy McLennan, Arijit Mukherji, Bradley Ruffle, Neil Wallace, Warren Weber, and especially Nobu Kiyotaki for useful comments and suggestions.     

Leading-by-example and signaling in voluntary contribution games: an experimental study

We report experimental results on the effect of leadership in a voluntary contribution game. Consistent with recent theories we find that leading-by-example increases contributions and earnings in an environment where a leader has private information about the returns from contributing (Hermalin in Am Econ Rev 88:1188–1206, 1998; Vesterlund in J Public Econ 87:627–657, 2003). In contrast the ability to lead-by-example has no effect on total contributions and earnings when such returns are commonly known. In our environment the success of leadership therefore appears to be driven by signaling rather than by nonpecuniary factors such as reciprocity. This paper was started while the authors were visiting the Harvard Business School during the fall of 2000. We are grateful for their hospitality and financial support. Vesterlund acknowledges support from the National Science Foundation and Potters from the Royal Netherlands’ Academy of Arts and Sciences. We thank Henrik Orzen for assistance in conducting the experiment. We also thank David Cooper and an anonymous referee who helped us improve the paper. Finally we thank Chris Anderson, Jim Andreoni, John Duffy, Simon Gaechter, Ernan Haruvy, Muriel Niederle, Jack Ochs, Elke Renner, Al Roth, participants at ESA-meetings (Barcelona, 2001), the Leadership and Social Interactions Workshop (Lyon, 2003), SITE (Stanford, 2004) and seminar participants at Alabama, CMU, Duke, Keele, Maryland, Nottingham, NYU, Pittsburgh, OSU, and York for valuable comments.     

The role of extensive and intensive margins and export growth

We investigate and compare countries' export growth based on their performance at the extensive and intensive export margins. Our empirical approach is motivated by an extension to the Melitz (2003) model of heterogeneous firms in which exporters are subject to a one-time sunk cost and also a per-period fixed cost. With imperfect information a firm may enter export markets but shortly exit when it learns its per-period fixed costs. We apply this insight to disaggregated export data and confirm that indeed most export relationships are very short lived. We then show that the survival issue is a significant factor in explaining differences in long run export performance. We find that developing countries would experience significantly higher export growth if they were able to improve their performance with respect to the two key components of the intensive margin: survival and deepening.