Finding a Nash equilibrium in spatial games is an NP-complete problem

Summary. We consider the class of (finite) spatial games. We show that the problem of determining whether there exists a Nash equilibrium in which each player has a payoff of at least k is NP-complete as a function of the number of players.Received: 15 September 2002, Revised: 9 March 2003, JEL Classification Numbers: C72.Correspondence to: H. HallerWe thank a referee for helpful comments. The hospitality of the Institute of Economics, University of Copenhagen, and the Institute for Advanced Studies, Vienna, is gratefully acknowledged by the third author.     

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.     

Voting in assemblies of shareholders and incomplete markets

Summary. An economy with two dates is considered, one state at the first date and a finite number of states at the last date. Shareholders determine production plans by voting - one share, one vote - and at -majority stable stock market equilibria, alternative production plans are supported by at most percent of the shareholders. It is shown that a -majority stable stock market equilibrium exists if where S is the number of states at the last date and J is the number of firms. Moreover, an example shows that -majority stable stock market equilibria need not exist for smaller s.Received: 23 December 2002, Revised: 14 June 2004, JEL Classification Numbers: D21, D52, D71, G39. Correspondence to: Hervé CrésThe authors are grateful to an anonymous referee for helpful comments and suggestions. Financial support from the Danish Research Councils and hospitality of HEC is gratefully acknowledged by Mich Tvede and support from Fondation HEC is gratefully acknowledged by Hervé Crés.     

Abstracts

Quality & Quantity -     

The optimal growth of the firm in a growing environment

The paper presents a growth model based on three essential assumptions: perfect knowledge of the future, descreasing returns on investment in a stagnant economy, appearance of new investment possibilities with the growth of the economy. Two cases are considered: the self-financing growth and the borrowing situation in the context of two management policies, the maximization of the discounted flow of dividends and the maximization of the growth rate.     

Incumbency advantage and its value

Markets with network effects are typically concentrated. The aim of this paper is to discuss some recent work on “incumbency advantage.” That is, the fact that firms already installed generate higher profits than entrants even if the latter offer identical or even better terms (in terms of price and quality) to consumers. In particular, we review recently known sources of the advantage and potential mitigating factors and point to a number of open issues.     

Female participation in African labor markets: The role of information and communication technologies

This article investigates the effects of information and communication technologies (ICT) on female labor force participation in a sample of 48 African countries. We specify and estimate linear regression and dynamic panel data models with fixed effects (FE) and system-generalized method of moments (SYS-GMM) estimation over the period 2001–2017. The three main results are that ICT use (mobile phone and internet) significantly stimulates female labor force participation in Africa; this effect is enhanced by financial development and female education; the effect of ICT on female employment in Africa is strongest in the industrial sector. These results remain robust to the provision of social, cultural, and institutional variables.     

WHICH AGGLOMERATION EXTERNALITIES MATTER MOST AND WHY?

This paper revisits the ongoing discussion on the importance of agglomeration externalities – specifically specialization, diversity and competition effects – that may contribute to innovation, productivity and urban employment growth. Previous meta‐analyses suggested that the evidence on agglomeration externalities is strongly context‐specific. Expanding an earlier analysis of 31 articles, we seek to draw in this paper more robust conclusions by means of the statistical evidence for agglomeration externalities presented in 73 scientific articles, all building on the seminal work of Glaeser et al. (1992). Our results confirm that the heterogeneity among studies is huge and can only be partially accounted for by means of an ordered probit analysis. Additionally, some evidence of publication bias is found. We conclude that the conventional lines of inquiry in this literature may now have reached strongly diminishing returns. New lines of inquiry, using rich micro‐level data on firms and workers, dynamic general equilibrium models at the macro level, more attention for spatial and temporal variation in the impacts of agglomeration, and further investigations into the spatial scope of externalities are promising avenues for further research that can enhance our understanding of how agglomeration externalities continue to fuel our increasingly urbanized world.