Information, trade and incomplete markets

The no-trade result of Milgrom and Stokey, J Econ Theory 26:17–27 (1982), states that if rational traders begin with an ex-ante Pareto optimal allocation then the arrival of information cannot generate trade. This paper allows traders to trade before and after the arrival of information. If there are enough securities to hedge against all payoff relevant risk, then the preinformation-arrival allocation is Pareto optimal and information arrival has no effect. This no-retrade result is the competitive analog of the no-trade result of (1982). However, information generically generates trade when markets are state-contingent incomplete.We thank seminar participants at Cambridge, Carnegie Mellon,Cornell, Essex, London, Maastricht, USC, and York and participants at the 2003 SITE, the 2003 SAET and the Fall 2002 Cornell–Penn State Macro Conference. We also thank Karl Shell and a referee for this journal for useful comments     

Group contest success functions

This paper extends the axiomatic characterization of contest success functions of Skaperdas (Econ Theory 7:283–290, 1996) and Clark and Riis (Econ Theory 11:201–204, 1998) to contests between groups. Comments by Dan Kovenock significantly improved the paper and are gratefully acknowledged. I would also like to thank Pavlo Blavatskyy, Aron Kiss, Kai Konrad, Florian Morath, Dana Sisak, participants of the SFB/TR 15 meeting in Gummersbach 2004, the 2004 meeting of the Verein für Socialpolitik in Dresden, and two anonymous referees. Any errors are mine. Financial support from the Deutsche Forschungsgemeinschaft through SFB/TR 15 is gratefully acknowledged.     

Optimal balanced growth in a general multi-sector endogenous growth model with constant returns

I will study a multi-sector endogenous growth model with general constant returns to scale technologies and demonstrate the existence, uniqueness and the saddle-path stability of the balanced growth equilibrium. I will first demonstrate the existence of a balanced growth equilibrium, by showing that the balanced growth rate associated with the balanced growth equilibrium is solely determined by solving a Frobenius root problem of the price equations derived from the Euler equations and the property of the nonsubstitution theorem. Then I will show the saddle-path stability of the balanced growth equilibrium without any capital intensity conditions, which is a generalized property proved in the two-sector endogenous growth models by de Guevara et al. (J Econ Dyn Control 21, 115–143, 1997), Bond et al. (J Econ Theory 68, 149–173 1996) and Mino (Int Eco Rev 37, 227–251 1996). The theorem clearly implies that the balanced growth equilibrium has a transition path in the neighborhood of the balanced growth equilibrium. The paper was presented at the conferences “Irregular Growth: Beyond Balanced Growth” held on June 19–21, 2003 in Paris and “Economic Growth and Distribution: On the Nature and Causes of the Wealth of Nations” held on June 16–18, 2004 in Lucca, Italy. From the discussion with Alain Venditti at CNRS-GREQAM, Gerhard Sorger at University of Vienna and the conference participants, I have been benefited much by writing this paper. Especially Alain Venditte had given me a chance to take a look at his unpublished paper titled ” Indeterminacy and the Role of Factor Substitutability” jointly written with Kazuo Nishimura at Kyoto University and published in Macroeconomic Dynamics, Vol. 8. The author also would like to thank an anonymous referee for useful suggestions.     

The Zilcha criteria for dynamic inefficiency reconsidered

We reconsider necessary and sufficient conditions for dynamic inefficiency given in Zilcha (J Econ Theory 52:364–379, 1990, J Econ Theory 55:1–16, 1991) and a critique by Rangazas and Russell (2005). First, we show that the characterization given in Zilcha (1990) for nonstationary economies is correct and correct Zilcha’s proof. Second, using this insight, we complement Rangazas and Russell’s (Econ Theory 26:701–716, 2005) discussion of the counterexamples to Zilcha (J Econ Theory 55:1–16, 1991). Third, we discuss consequences of our results for applied tests of (in-)efficiency based on the Zilcha criteria. We would like to thank Itzhak Zilcha, and in particular Peter Rangazas and Steve Russell for detailed and very helpful comments.     

Firm heterogeneity and Ricardian comparative advantage within and across sectors

This paper incorporates Melitz’s Econometrica (71:1695–1725, 2003) heterogeneous-firm trade model in the Ricardian model of comparative advantage with a continuum of sectors introduced by Dornbusch et al. (Am Econ Rev 67(5), 823–839, 1977). In particular, we characterise the equilibrium outcomes when neither sectors nor countries are symmetric. We find that trade patterns can follow Ricardian comparative advantage, while wage rates are proportional to market size due to a home market effect. Interestingly, trade liberalisation hurts the large country but benefits the small one by reducing the number of sectors with two-way trade and expanding those with specialised (one-way) trade. I would like to thank Mike Artis, Richard Baldwin, Frederic Robert-Nicoud, Matthias Helble, Giovanni Facchini, Thierry Verdier and a referee for their helpful comments and suggestions. Also I would like to thank Mike Artis for his excellent proof reading.     

Debreu’s social equilibrium theorem with asymmetric information and a continuum of agents

We provide several different generalizations of Debreu’s social equilibrium theorem by allowing for asymmetric information and a continuum of agents. The results not only extend the ones in Kim and Yannelis (J Econ Theory 77:330–353, 1977), Yannelis and Rustichini (Stud Econ Theory 2:23–48, 1991), but also new theorems are obtained which allow for a convexifying effect on aggregation (non-concavity assumption on the utility functions) and non-convex strategy sets (pure strategies). This is achieved by imposing the assumption of “many more agents than strategies” (Rustichini and Yannelis in Stud Econ Theory 1:249–265, 1991; Tourky and Yannelis in J Econ Theory 101:189–221, 2001; Podczeck in Econ Theory 22:699–725, 2003). To the memory of Gerard Debreu. A preliminary draft was presented in Paris, in April of 2005. I have benefited from the discussion, comments and questions of Erik Balder, Jean-Marc Bonnisseu, Bernard Cornet and Filipe Martins Da-Rocha and Conny Podczeck. A careful and knowledgeable referee made several useful comments and rescued me from a mishap.     

Forward induction and entry deterrence: an experiment

The Dixit (Econ J 90:95–106, 1980) hypothesis that incumbents use investment in capacity to deter potential entrants has found little empirical support. Bagwell and Ramey (J Econ 27:660–680, 1996) propose a model where, in the unique game-theoretic prediction based on forward induction or iterated elimination of weakly-dominated strategies, the incumbent does not have the strategic advantage. We conduct an experiment with games inspired by these models. In the Dixit-style game, the incumbent monopolizes the market most of the time even without the investment in capacity. In our Bagwell-and-Ramey-style game, the incumbent also tends to keep the market, in contrast to the predictions of an entrant advantage. Nevertheless, we find strong evidence that forward induction affects the behavior of most participants. The results of our games suggest that players perceive that the first mover has an advantage without having to pre-commit capacity. In our Bagwell–Ramey game, evolution and learning do not drive out this perception. We back these claims with data analysis and a theoretical framework for dynamics. Financial support by the Spanish Ministerio de Ciencia and Tecnología (SEC2002-01352 and SEJ2006-11665-C02-01) and the Barcelona Economic Program of CREA and excellent research assistance by David Rodríguez are gratefully acknowledged. The authors thank Aurora García Gallego and Armin Schmutzler for helpful comments.     

Post-earnings announcement drift: Spanish evidence

This paper analyses whether earnings announcements in the Spanish stock market are followed in subsequent months by a return drift in the same direction as the earnings surprise. Two alternative earnings surprise measures are used and they both provide strong post-earnings announcement drifts. In order to find an explanation for this anomaly we first make several unconditional adjustments, which include the CAPM, the Fama–French (J Financ Econ 33:3–56, 1993) three-factor model, a liquidity factor, controlling portfolios by size and book-to-market ratio, and controlling for the momentum effect. Second, we make a conditional analysis following two different approaches: (i) studying the relation with the business cycle and (ii) studying whether this phenomenon can be explained through a conditional version of the CAPM and the Fama-French model. None of these adjustments are able to satisfactorily capture the Spanish post-earnings announcement drift. A final analysis offers some slight evidence in favour of the limits-to-arbitrage explanation. A previous version of this paper is available in the Working Paper Series of FUNCAS (no. 221, 2005), who we thank for their collaboration in the research diffusion in Spain. We also acknowledge the financial support of the Ministerio de Ciencia y Tecnología (SEJ2005-09372/ECON), Conselleria d’Empresa, Universitat i Ciència (GV06/196) and University of Alicante (GRJ06-03). This version has benefited from interesting comments made by Gonzalo Rubio, Belén Nieto, Natividad Blasco, Renata Herrerías and Carina Sponholtz, as well as by various anonymous referees. Any remaining errors are the sole responsibility of the authors.     

On discounted dynamic programming with unbounded returns

In this paper, we apply the idea of k-local contraction of Rincón-Zapatero and Rodriguez-Palmero (Econometrica 71:1519–1555, 2003; Econ Theory 33:381–391, 2007) to study discounted stochastic dynamic programming models with unbounded returns. Our main results concern the existence of a unique solution to the Bellman equation and are applied to the theory of stochastic optimal growth. Also a discussion of some subtle issues concerning k-local and global contractions is included.     

Large economies with differential information and without free disposal

We consider exchange economies with a continuum of agents and differential information about finitely many states of nature. It was proved in Einy et al. (Econ Theory 18, 321–332, 2001) that if we allow for free disposal in the market clearing (feasibility) constraints then an irreducible economy has a competitive (or Walrasian expectations) equilibrium, and moreover, the set of competitive equilibrium allocations coincides with the private core. However when feasibility is defined with free disposal, competitive equilibrium allocations may not be incentive compatible and contracts may not be enforceable (see e.g. Glycopantis et al. in Econ Theory 21, 495–526, 2002). This is the main motivation for considering equilibrium solutions with exact feasibility. We first prove that the results in Einy et al. (Econ Theory 18, 321–332, 2001) are still valid without free-disposal. Then, motivated by the issue of contracts’ execution, we adapt the incentive compatibility property introduced in Krasa and Yannelis (Econometrica 62, 881–900, 1994) and we prove that every Pareto optimal exact feasible allocation is incentive compatible, implying that contracts of competitive or core allocations are enforceable. We would like to thank two anonymous reviewers and the Associate Editor for their valuable suggestions and remarks. This work was partially done while V.F. Martins-da-Rocha was visiting the Dipartimento di Matematica e Informatica of the Università degli Studi di Perugia. We thank the audience of the First General Equilibrium Workshop at Rio. Section 6 dealing with contract enforcement and coalitional incentive compatibility has benefited from discussions with J. Correia-da-Silva, W. Daher, F. Forges, C. Hervès-Beloso, E. Moreno-García, K. Podczeck, Y. Vailakis and N.C. Yannelis.     

Multi-lender coalitions in costly state verification models

The paper analyzes the endogenous formation of a financial intermediary, modelled as a multi-lender coalition, as the trade-off between economies of scale in monitoring and a ‘cost’ associated with the partial loss of control over the investments the multi-lender coalition makes. In contrast with previous contributions (e.g., Williamson in J Monet Econ 18:159–179, 1986), the model can account for the coexistence of financial intermediation and direct lending (a non-trivial equilibrium). We prove the existence of such non-trivial equilibria and provide a complete characterization of them. In particular, the stronger the diversity of opinions, the smaller the coalition size is. I owe Pierpaolo Battigalli and Larry Samuelson a special debt for their insightful comments and encouragements. I am also grateful to the co-editor, Stephen Williamson, and an anonymous referee for insightful comments. I also like to thank Rabah Amir, Francis Bloch, Guillaume Carlier, Pascal Courty, Martin Hellwig, Bart Lipman, Jean-Marc Tallon and Anne Villamil for helpful discussions. Finally, I thank the THEMA, University Cergy-Pontoise, where part of this paper was written, for their hospitality.     

Lotteries, inequality, and market imperfection: Galor and Zeira go gambling

This paper analyzes a simple extension to the work of Galor and Zeira (Rev Econ Stud 60:35–52, 1993). Allowing for endowment lotteries alters the dynamics of the model fundamentally: the poverty trap found in the original work vanishes for a wide class of parameters. Moreover, it turns out that in the presence of lotteries the relationship between the severity of credit market imperfections and long run aggregate income may be non-monotonic. We identify cases such that reducing the scope for moral hazard on the capital market decreases aggregate utility and may create a poverty trap and persistent income inequality in the economy. I am grateful for many helpful comments to Hans-Peter Grüner and an anonymous referee and for valuable discussion to Stefan Behringer and Petr Zemčík, and to seminar participants at Mannheim University and ENTER Jamboree 2003, Tilburg. Financial support from DFG is gratefully acknowledged.     

Changes in the Austrian structure of wages, 1996–2002: evidence from linked employer-employee data

Analyzing data from the Structure of Earnings Surveys we find that wage dispersion in Austria increased only marginally between 1996 and 2002. There was an increase in the returns to education which accrued only to male workers. The positive effects of tenure and especially of experience on wages decreased over time. We adopt the Machado–Mata (J Appl Econ 20:445–465, 2005) counterfactual decomposition technique which allows to attribute changes in each wage decile to changes in worker and workplace characteristics and into changes in returns to these characteristics. Behind the small net increase in inequality we document a number of interesting gross effects that influence the change in the wage distribution. We find that both composition effects due to gender, education and age and market-driven effects such as changes in returns and changing workplace characteristics contributed to a higher dispersion of wages.     

Market crashes,speculation and learning in financial markets

A natural conjecture is that if agents’ beliefs are almost correct then equilibrium prices should be close to rational expectations prices. Sandroni (J Econ Theory 82:1–18, 1998) gives a counterexample in an economy with sunspots and complete markets. We extend Sandroni’s result by showing that the conjecture is generically true for economies with complete markets. We consider a standard General Equilibrium model with large but finite horizon and complete markets. We show that, for almost every such economy, if conditional beliefs eventually become correct along a path of events then equilibrium prices of assets traded along this path converge to rational expectations equilibria in the sup-norm. Moreover, we establish that, generically, there exist along any such path local diffeomorphisms between individual beliefs and equilibrium prices. I would like to thank C. Ewerhart and A. Kirman for their comments, as well as the seminar participants at the University of Minho, the General Equilibrium Workshop 2005 in Zurich, and the 15th Asian General Equilibrium Conference 2007 in Singapore. An anonymous referee also provided very valuable comments.     

Optimal pricing of a two-sided monopoly platform with a one-sided congestion effect

This paper studies the optimal pricing of a two-sided monopoly platform when one side is affected by congestion. We show that the divide-and-conquer pricing strategy (or skewed pricing) depends not only on the relative magnitude of the sides’ price elasticities of demand but it also depends on the marginal congestion cost that an agent imposes on the others. Compared with the no-congestion case, this pricing strategy gives rise to some interesting features that violate the results of Rochet and Tirole (J Eur Econ Assoc 1:990–1029 in 2003, Rand J Econ 37:645–667 in 2006). In the case of equal price elasticities of demand, the no-congested side is charged the highest price. On the other hand, in the case of different price elasticities, the platform congestion pricing depends on a certain threshold of the marginal congestion cost. We show, under some conditions, that the divide-and-conquer pricing strategy is reversed. In the social context, the Rochet and Tirole’s (J Eur Econ Assoc 1:990–1029 in 2003) cost allocation condition is modified by the congestion cost. We show that the congestion does not only affect the buyers’ contribution to the sellers’ surplus, but it also affects the sellers’ contribution to the buyers’.     

Expected consumer’s surplus as an approximate welfare measure

Except for a knife-edge case of preferences, the percentage error from using the change in expected consumer’s surplus (ECS) to approximate the willingness to pay for a change in the distribution of a random price is unbounded, in contrast to Willig’s (Am Econ Rev 66:589–597; 1976) famous approximation result for nonrandom prices. If the change is smooth on the space of random variables, and either the initial price is nonrandom or state-contingent payments are possible, then the change in ECS locally approximates the willingness to pay well. Unfortunately, this smoothness fails in some important applications. I thank Hector Chade, Glenn Ellison, Peter Hammond, Manuel Santos, seminar participants at Arizona State, Stanford and Yale and participants of the Midwest Economic Theory meetings at Indiana University and the 2004 Summer Econometric Meetings for comments.     

A flexible time-varying specification of the technical inefficiency effects model

The temporal pattern of technical efficiency in the technical inefficiency effects model, as modeled by Battese and Coelli (Empir Econ 20:325–332, 1995), is rather restrictive. Specifically, it a priori imposes a common pattern upon all firms in the sample, which in addition is monotonic over time. Obviously this is an undesirable implication of the model especially when there is evidence of strong firm heterogeneity and/or a long time span. To overcome this shortcoming, the present paper incorporates the Cornwell et al. (J Econom 46:185–200, 1990) flexible specification of the temporal pattern of technical efficiency into technical inefficiency effects model. The proposed formulation is then applied to the agricultural sector of the EU and US, during the period 1973–1993. The empirical result support the proposed formulation as quite different temporal patterns of technical efficiency have been found for the ten countries included in the analysis. We would like to thank an anonymous referee and an associate editor for valuable suggestions in an earlier version of the paper.     

Estimating the natural rates in a simple New Keynesian framework

The time-varying natural rate of interest and output and the implied medium-term inflation target for the US economy are estimated over the period 1983–2005. The estimation is conducted within the New Keynesian framework using Bayesian and Kalman-filter estimation techniques. With the model-consistent estimate of the output gap, we get a small weight on the backward-looking component of the New Keynesian Phillips curve—similar to what is obtained in studies which use labor share of income as a driver for inflation (e.g., Galí, Eur Econ Rev 45(7):1237–1270, 2001; Eur Econ Rev 47(4):759–760, 2003). The turning points of the business cycle are nevertheless broadly consistent with those of CBO/NBER. We find considerable variation in the natural rate of interest while the inflation target has been close to 2% over the last decade.