1,721,049 research outputs found
Une présentation simple des dynamiques complexes
No full textA simple presentation of complex dynamics
In this paper we systematically investigate the dynamical properties of the overlapping generations model a la Samuelson, and their link with the savings function. When the substitution effect dominates the income effect, the dynamics is monotone. When the income effect dominates the substitution effect, the dynamics oscillates and a cycle of period 2 may exists. And when the savings function is not monotonie, it may exist cycles of every period and chaotic trajectories.Une présentation simple des dynamiques complexes
Sous sa forme la plus simple, le modèle à générations imbriquées utilise les propriétés dynamiques des évolutions non linéaires en dimension un. Dans l'étude de ce modèle, nous explorons systématiquement ces propriétés et leurs relations avec la forme de la fonction d'épargne. Quand l'effet de substitution domine l'effet de revenu, la dynamique est monotone. Quand l'effet de revenu domine l'effet de substitution, la dynamique est oscillante, et il peut y avoir des cycles de période deux. Quand l'épargne n'est pas une fonction monotone du taux d'intérêt, il peut y avoir des cycles de période quelconque et il peut y avoir des trajectoires chaotiques.Michel Philippe, Wigniolle Bertrand. Une présentation simple des dynamiques complexes. In: Revue économique, volume 44, n°5, 1993. pp. 885-912
Contraintes de liquidités dans le modèle à générations imbriquées de Diamond. Neutralité des politiques monétaires et dynamique macroéconomique
No full textCash-in-advance constraints in the overlapping generations model : neutrality of monetary policies and macro-dynamics
This article is concerned with the role of money in an O.L.G. model. Money is introduced through a cash-in-advance constraint. We show that money is super-neutral if the structure of money repartition does not depend on the money growth rate. We study the dynamics, and the influence of money transfers on capital accumulation.Cash-in-advance constraints in the overlapping generations model : neutrality of monetary policies and macro-dynamics
This article is concerned with the role of money in an O.L.G. model. Money is introduced through a cash-in-advance constraint. We show that money is super-neutral if the structure of money repartition does not depend on the money growth rate. We study the dynamics, and the influence of money transfers on capital accumulation.Michel Philippe, Crettez Bertrand, Wigniolle Bertrand. Contraintes de liquidités dans le modèle à générations imbriquées de Diamond. Neutralité des politiques monétaires et dynamique macroéconomique. In: Revue économique, volume 49, n°3, 1998. pp. 677-685
Vers des sociétés vertes
No full textAu cours des dernières années, la question de l’environnement prend de l’importance. A mesure que la population mondiale, ainsi que la consommation d’énergie par habitant, croissent, nous atteignons, à certains égards, les limites planétaires. Actuellement, personne ne doute que le changement climatique qui en résulte est réel et sérieux. Nous observons aussi d’autres problèmes environnementaux dus à l’activité humaine, tels que la surpêche ou la perte de biodiversité. En considérant ces phénomènes, on a l’impression qu’en tant qu’individus ainsi qu’en tant que sociétés , nous ne sommes pas capables de prendre soin de l’environnement dans lequel nous vivons. Nous pouvons constater de grandes différences dans le comportement environnemental des personnes, ainsi que des pays, au travers des leurs politiques publiques mises en place. Bien que les raisons de ces différences aient été étudiées dans la littérature, certaines questions restent à explorer et ce sont elles qui ont poussé mon étude. Les questions auxquelles je tente de répondre structurent les trois chapitres de cette thèse.This paper aims to provide an alternative explanation for why countries behave differently with respect to the environment and contributions to global pollution, although they might be quite similar from an economic development point of view. To explore this idea, I use a simple micro-founded model in which individuals derive utility from their own well-being as well as from a moral standpoint. The utility of the latter concept comes from the idea that individuals derive satisfaction from doing ‘the right thing’ (at least to some degree) – or, according to Immanuel Kant, from behaving according to the imperative principle. Being or acting green could fall into the category of such imperative principles. Using these concepts in addition to a simple political framework, I show that two equivalent societies (i.e., societies with the same income, political system, etc.) can reach two different environmental behaviour equilibria. I also locate the means of nudging a society from one equilibrium to another. Although I do not claim that this explanation is the only reason for why countries behave differently, this model provides a very simple rationale for why this could happen
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Savings behavior with imperfect capital markets: when hyperbolic discounting leads to discontinuous strategies
Full text linkInternational audienceThis paper provides a detailed study of a simple life-cycle consumption model with quasi-hyperbolic discounting and an imperfect financial market. It gives a complete characterization of savings behavior. The joint assumptions of quasi-hyperbolic discount factors and no-borrowing constraints may lead to non-convexities in selves' objective functions that may imply discontinuous equilibrium strategies. The savings function may undergo jumps and non-monotonicities when the income or the interest rate reaches a threshold value. These ''anomalies'' may exist even for reasonable parameter values
Fertility in the absence of self-control
No full textInternational audienceThis paper studies the quantity-quality trade-off model of fertility, under the assumption of hyperbolic discounting. It shows that the lack of self-control may play a different role in a developed economy and in a developing one. In the first case, characterized by a positive investment in quality, the lack of self-control may tend to reduce fertility. In the second case, it is possible that the lack of self-control leads to both no investment in quality and a higher fertility rate. It is also proved that if parents cannot commit on their investment in quality, a small change of parameters may lead to a jump in fertility and education
Fertility in the absence of self-control
Full text linkURL des Documents de travail : http://ces.univ-paris1.fr/cesdp/CESFramDP2008.htmClassification JEL : D91, J13, O12.Documents de travail du Centre d'Economie de la Sorbonne 2008.68 - ISSN : 1955-611XThis paper studies the quantity-quality trade-off model of fertility, under the assumption of hyperbolic discounting. It shows that the lack of self-control may play a different role in a developed economy and in a developing one. In the first case characterized by a positive investment in quality, the lack of self control tends to reduce fertility. In the second case, it is possible that the lack of self-control leads both to no investment in quality and to a higher fertility rate. It is also proved that if parents cannot commit on their investment in quality, a small change of parameters may lead to a jump in fertility.Ce travail étudie le modèle de choix de fécondité reposant sur un arbitrage entre quantité et qualité des enfants, sous l'hypothèse d'escompte hyperbolique. Il montre que le manque de contrôle de ses êtres successifs peut avoir un effet différent selon que l'économie est développée ou en développement. Dans le premier cas caractérisé par un investissement positif dans la qualité des enfants, l'absence de contrôle réduit la fécondité. Dans le second, l'absence de contrôle peut accroître la fécondité et annuler l'investissement en qualité. Enfin, il est montré qu'en l'absence d'engagement, une faible variation d'un paramètre peut produire une forte variation de fécondité
Croissance, innovations organisationnelles et progrès technique biaisé
No full textGrowth, Organisational Innovations and Biased Technical Progress.
This article suggests that the biased technical progress observed in the Western world during the last twenty years is due to organisational innovations. To show this, we explore an endogenous growth model in which businesses use an O-ring type production technology. It is assumed that organisational innovations may appear during every period. These new technologies are adopted only by businesses using highly skilled labour and bring about technical progress slanted in favour of workers with the best skills. When the labour market is non-competitive, innovations may worsen unemployment among the least skilled workers. But they always increase the economic growth rate.Cet article propose une interprétation du progrès technique biaisé, observé dans les pays occidentaux ces vingt dernières années, comme la conséquence d''innovations organisationnelles. Pour ce faire, on développe un modèle de croissance endogène dans lequel les entreprises disposent d''une technologie de production de type O-ring. A chaque période, l'on suppose que des innovations organisationnelles peuvent apparaître. Ces nouvelles technologies sont adoptées uniquement par les entreprises qui utilisent les travailleurs les plus qualifiés et elles induisent un progrès technique biaisé en faveur des plus qualifiés. Lorsque le marché du travail est non-concurrentiel, les innovations peuvent entraîner une augmentation du chômage chez les travailleurs les moins qualifiés. Dans tous les cas, elles augmentent le taux de croissance de l'économie.Wigniolle Bertrand. Croissance, innovations organisationnelles et progrès technique biaisé. In: Économie & prévision, n°150-151, 2001-4-5. pp. 159-170
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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