Increasing Returns to Scale and Welfare: Ranking the Multiple Deterministic Equilibria

We consider a real business cycle model with a productive externality and an aggregate non- convex technology set µa la Benhabib and Farmer embodying capacity utilization, which exhibits indeterminacy of the steady state and multiplicity of deterministic equilibria under plausible values of the increasing returns to scale. The aim of the paper is to rank these different equilibria according to the initial value of consumption using both a linear-quadratic approximation, extensively explained by Benigno and Woodford [2006a, 2006b], and simulation methods. We study the implications of such a ranking in terms of smoothness of the welfare-maximizing trajectory and show that the welfare- maximizing consumption and labor paths are all the smoother since the level of increasing returns is low. At last, we show that this solution provides a good benchmark for judging the desirability of the stabilization policy proposed by Guo and Lansing [1997].Increasing returns, Local indeterminacy, Welfare analysis, Numerical Methods

Unconditionnally stable scheme for Riccati equation

We present a numerical scheme for the resolution of matrix Riccati equation used in control problems. The scheme is unconditionnally stable and the solution is definite positive at each time step of the resolution. We prove the convergence in the scalar case and present several numerical experiments for classical test cases.Comment: 11 page

Grand corps et mini-États ou l’image d’un tout ce que nous sommes en Tunisie

Cet article traite de deux questions principales : le corps et l’État. L’auteur prend le cas de figure d’un spectacle de danse qui était produit et diffusé au cours des années 1990 en Tunisie. Intitulé « Nouba », ce spectacle fournit les appuis empiriques nécessaires pour que l’idée faisant de l’État un Grand Corps et du corps un mini-État ne se limite point à la métaphore, mais s’attache plutôt à la réalité. En effet, cette idée a permis à l’auteur d’appréhender le pays et le spectacle l’un à la lumière de l’autre, tout en portant l’analyse hors des sentiers battus. Cela dit, le fait que l’article traite de la question du corps dans une société arabo-musulmane ne l’implique pas automatiquement dans la sphère des études orientalistes ou islamologiques. Autrement dit, ce n’est pas de l’interdit que l’on discute dans ce texte, mais plutôt de l’inter-dit.This article covers two main questions: the body and the State. The author uses a dance act that was produced and aired in the 1990s in Tunisia as a case study. Entitled “Nouba”, this dance act provides empirical evidence that the idea of the State as a large body and the body as a miniature State is a reality rather than mere metaphor. As such, this idea allowed the author to represent the country and the dance act in light of one another, while allowing the analysis to go beyond conventional thinking. That having been said, the fact that the article discusses the body in an Arabic/Muslim society did not automatically confine the author to the field of orientalist and islamic studies. In other words, this text does not discuss the forbidden but rather invites us to read between the lines

Galois Covers of Degree p and Semi-stable Reduction of Curves in Equal Characteristic p>0

In this paper we study the semi-stable reduction of Galois covers of degree p above curves over a complete discrete valuation ring of equal characteristic p.</p

The cuspidalisation of sections of arithmetic fundamental groups II

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordIn this paper, which is a sequel to [7], we investigate the theory of cuspidalisation of sections of arithmetic fundamental groups of hyperbolic curves to cuspidally i-th and 2/p-th step prosolvable arithmetic fundamental groups. As a consequence we exhibit two, necessary and sufficient, conditions for sections of arithmetic fundamental groups of hyperbolic curves over p-adic local fields to arise from rational points. We also exhibit a class of sections of arithmetic fundamental groups of p-adic curves which are orthogonal to Pic∧, and which satisfy (unconditionally) one of the above conditions

Do followers really matter in Stackelberg competition?

In this note, we consider a generalized T−stage Stackelberg oligopoly. We provide a proof and an interpretation that under the two necessary and sufficient conditions of linear aggregate demand and identical constant marginal costs, followers do not matter for leaders. Leaders act as rational myopic agents, voluntarily ignoring the number of followers and remaining stages, thereby behaving as Cournotian oligopolists. Strategies of incumbent firms are invariant to entry of new cohorts. Their profits can be studied by the way of two discount factors: the first impacting markup and the second impacting output supply. Some implications in terms of welfare and convergence toward competitive equilibrium are derived.Leader’s markup discount factor, linear economy, follower’s output discount factor, myopic behavior