Voluntary Participation in a Mechanism Implementing a Public Project

In this study, a participation game in a mechanism to implement a public project is considered; in this game, agents decide simultaneously whether they will participate in the mechanism or not. We characterize the sets of participants at strict Nash equilibria, strong equilibria, and coalition-proof equilibria of the participation game. The three sets of equilibria are shown to coincide and exist. All the equilibrium allocations are Pareto efficient at any one of three notions of equilibria. However, if the public good can be provided in multiple units or if there are multiple projects, then these sets may fail to coincide.Participation game, Public project, Strong equilibrium, Coalition-proof equilibrium, Multi-unit public good, Multiple projects

Diverse societal beliefs and redistributive policies, but equal welfare: The trade-off effect of information

Large empirical evidence shows that the difference in the political support for redistribution appears to reflect a difference in the social perceptions regarding the determinants of individual wealth and the underlying sources of income inequality. This paper presents a model of beliefs and redistribution which explains this evidence through multiple politico-economic equilibria. Differently from the recent literature which obtains multiple equilibria by modeling agents characterized by psychological biases, my model is based on standard assumptions. Multiple equilibria originate from multiple optimal levels of information for the society. Multiple optimal levels of information exist because increasing the informativeness of an economy produces a trade-off between a decrease in adverse selection and an increase in moral hazard. The framework allows to analyze various comparative statics in order to answer to policy questions

Complementarities, Costly Investment and Multiple Equilibria in a One-Sector Endogenous Growth Model

In this paper we develop a multiple equilibria one-sector R&D-based growth model, in which the key aspects are the assumption of complementarities between capital goods in the production function and the assumption of costly investment in capital. This second assumption is new to the R&D-based literature. The equilibrium solutions are obtained when the Preferences curve, which mirrors consumers’ savings decisions, and the Technology curve, which represents equilibria on the production side, cross. The combination of the two key assumptions produces a non-linear Technology curve, which consequently crosses the Preferences curve more than once, thus generating multiple equilibria. A numerical solutions exercise obtains two equilibria. Application of the stability under learning criterion allows for the identification of the two equilibria as stable. Expectations can lead the economy to either the equilibrium characterised by high-growth and high-interest rates, or to the equilibrium characterised by low-growth and low-interest rates. Hence, with this model, we wish to contribute to endogenous growth literature by providing a mechanism to explain how an economy can experience multiple equilibria situations.Growth, R&D, complementarities, costly investment, multiple equilibria.

Looking for Multiple Equilibria when Geography Matters: German City Growth and the WWII Shock

Many modern trade and growth models are characterized by multiple equilibria. In theory the analysis of multiple equilibria is possible, but in practice it is difficult to test for the presence of multiple equilibria. Based on the methodology developed by Davis and Weinstein (2004) for the case of Japanese cities and WWII, we look for multiple equilibria in a model of German city growth. The strategic bombing of Germany during WWII enables us to assess the empirical relevance of multiple equilibria in a model of city-growth. In doing so, and in addition to the Davis and Weinstein framework, we look at the spatial inter-dependencies between cities. The main findings are twofold. First, multiple equilibria seem to be present in German city growth. Our evidence supports a model with 2 stable equilibria. Second, the explicit inclusion of geography matters. Evidence for multiple equilibria is weaker when spatial interdependencies are not taken into account.

Human Capital Externalities with Monopsonistic Competition

This paper provides a novel microeconomic foundation for pecuniary human capital externalities in a labor market model of monopsonistic competition. Multiple equilibria arise because of a strategic complementarity in investment decisions.externalities, human capital, multiple equilibria

Consumer confusion and multiple equilibria

This paper focuses on consumer confusion when firms may choose between credible and non-credible certification systems for signalling quality. It is shown that the presence of confused consumers leads to the emergence of multiple stable equilibria, in which either all firms select the credible certification or all firms select the non-credible certification. A situation with numerous confused consumers is characterized by the complete absence of credible certification.Quality, certification

Financial Fragility, Liquidity and Asset Prices

A financial system is fragile if a small shock has a large effect. Sunspot equilibria, where the endogenous variables depend on extrinsic uncertainty, provide an extreme illustration. However, fundamental equilibria, where outcomes depend only on intrinsic uncertainty, can also be fragile. We study the relationship between sunspot equilibria and fundamental equilibria in a model of financial crises. The amount of liquidity is endogenously chosen and determines asset prices. The model has multiple equilibria, but only some of these are the limit of fundamental equilibria when the fundamental uncertainty becomes vanishingly small. We show that under certain conditions the only robust equilibria are those in which extrinsic uncertainty gives rise to asset price volatility and Þnancial crises.

Uniqueness of Nash equilibria in quantum Cournot duopoly game

A quantum Cournot game of which classical form game has multiple Nash equilibria is examined. Although the classical equilibria fail to be Pareto optimal, the quantum equilibrium exhibits the following two properties, (i) if the measurement of entanglement between strategic variables chosen by the competing firms is sufficiently large, the multiplicity of equilibria vanishes, and, (ii) the more strongly the strategic variables are entangled, the more closely the unique equilibrium approaches to the optimal one.Comment: 7 pages, 2 figure

Non-Market Interactions

A large body of recent research argues that social, or non-market, interactions can explain a wide range of puzzling phenomena from fashion cycles to stock market crashes. This paper attempts to connect the range of these papers with a general model and a broad empirical overview. We establish conditions for existence and uniqueness of equilibria in social interactions models. The existence of multiple equilibria requires sufficient non-linearity in social interactions and only moderate heterogeneity across agents--strategic complementarities are neither necessary nor sufficient for multiple equilibria. We establish conditions for the existence of a social multiplier, which is the ratio of the aggregate outcome-input relationship to the individual outcome-input relationship. Models with multiple equilibria are empirically indistinguishable from models with significant social multipliers. Finally, we show the formal relationship between three known methods of empirically estimating social interactions, and suggests the plusses and minuses of these three approaches.

Pure Strategies and No Externalities with Multiple Agents

This note considers two properties of common agency models - pure strategy equilibria with simple competition are robust and equilibria in mechanisms can be reproduced as equilibria with simple competition provided an appropriate no-externalities assumption holds. This note provides counter examples to both these theorems when there are multiple agents.