1,720,958 research outputs found
A remark on definable paths in regular O-minimal equilibrium manifolds
Full text linkThe main purpose of this paper is to remark that any definable continuous path linking two regular equilibria in a regular O-minimal equilibrium manifold intersects a finite number of definable connected components locally determined. We apply the cell decomposition theorem to decompose the definable equilibrium manifold in finite connected components, the definable triviality theorem to local determinacy in each component, and the definable curve selection to have continuous paths in the manifold
On the pseudo-equilibrium manifold in semi-algebraic economies with real financial assets
Full text linkThe aim of this paper is to prove that if the consumption set of an economy with incomplete financial markets is semi-algebraic, then the corresponding pseudo-equilibrium manifold is also semi-algebraic. For this, we proceed by constructing an incomplete financial economy with real assets and semi-algebraic utility functions. Then, we show that the spot-equilibrium set and the pseudo-equilibrium set are smooth semi-algebraic manifolds. We extent this results by showing that the pseudo-equilibrium natural projection is a semi-algebraic diffeomorphism in each regular point of the semi-algebraic pseudo-equilibrium
manifold. It is directly related with the local determinacy of pseudo-equilibrium
A condition for determinacy of optimal strategies in zero-sum convex polynomial games
Full text linkThe main purpose of this paper is to prove that if there is a non-expansive map relating the sets of optimal strategies for a convex polynomial game, then there exists only one optimal strategy for solving that game. We introduce the remark that those sets are semi-algebraic. This is a natural and important property deduced from the polynomial payments. This property allows us to construct the space of strategies with an infinite number of semi-algebraic curves. We semi-algebraically decompose the set of strategies and relate them with non-expansive maps. By proving the existence of an unique fixed point in these maps, we state that the solution of zero-sum convex polynomial games is determined in the space of strategies
A short note on the definable Debreu map in regular O-minimal equilibrium manifolds
Full text linkThe main purpose of this paper is to outline that the definable Debreu map is a local definable diffeomorphism. It implies the equilibrium is locally determined in each connected component partitioning a regular O-minimal equilibrium manifold. It complements the result in Theorem 5 of Arias-R. (2013) and converges to the local determinacy result of definable competitive equilibrium of Blume and Zame (1992)
From monopsonistic insurgent groups to oligopolistic cocaine traffickers: the market of cocaine in Colombia
Full text linkThe main purpose of this note is to model an imperfect competitive and vertically integrated market structure of production and trafficking of cocaine. We consider the particular case of colombian cocaine market, but the results could be generalized to different scenarios.
We model three main participants: farmers, producing the coca-leaf and being price-takers in its market; insurgent groups, producing paste of cocaine and being a local monopsony in the coca-leaf market; and cocaine traffickers, being an oligopoly competing a la Cournot. We find
out an explicit relationship between the price of coca-leaf and paste of cocaine, with the coca-leaf elasticity of supply. An inelastic coca-leaf supply allows the insurgent groups to increase the gap between the price of coca-leaf and the price of the paste of cocaine. Additionally, the
insurgent groups obtain important profits from the oligopolistic market structure of cocaine market, because the increase in the price of cocaine also increases the price of paste of cocaine, through the increase in its demand. These profits feed every step in the pyramid of cocaine production exacerbating the problem and making more difficult its solution. These remarks others important information to explain the reasons behind the ineffectiveness of some national and international policies in the war against illegal drugs
Land control or interdiction? Searching for a clue in the colombian cocaine market
Full text linkThe purpose of this note is to estimate the relative impact of interdiction and land control on the colombian cocaine market. The government interdicts part of the cocaine traffic and controls part of the arable land with the aim of weakening this illegal market. Our estimation depends on the price elasticity of the coca-leaf supply, in particular, the importance of the land with respect to other factors in the production of coca-leaf
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
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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