Modelling Behavioral Heterogeneity.

If one wants to get rid of the paradoxes pointed out by Hildenbrand (1998) and B. de Villemeur (1999), one needs to reformulate Grandmont's (1992) notion of behavioral heterogeneity such as to get exact insensitivity of the aggregate budget share function with respect to changes in prices and income, instead of a mere approximate insensitivity. Here, we propose a non parametric set-up such that, if the population is distributed according to some ``uniform'' measure, the aggregate budget share function is constant. This exact insensitivity is not explained by any insensitivity property at the micro-economic level, but rather by a perfect ``balancing effect''. We then discuss the economic interpretation of some concrete examples illustrating our theory.Aggregation of demand, behavioral heterogeneity, large economy, Law of Demand, Insensitivity of market budget shares.

Behavioral Heterogeneity in Large Economies

Grandmont\'s ([14]) notion of behavioral heterogeneity is reformulated in a non parametric set-up such that the space of budget share functions admits a ``uniform\'\' probability distribution. If the population is distributed according to this measure, the aggregate budget share function is constant with respect to changes in prices and income. This exact insensitivity of the market budget share function is known to imply uniqueness and global stability of any competitive equilibrium. Here, it is not explained by any insensitivity property at the micro-economic level, but rather by a perfect \'balancing effect\'. Eventually, it is proved that the insensitivity property holds approximately for a finite population sufficiently close to, but distinct from, the perfectly heterogenous one.Aggregation of demand, behavioral heterogeneity, large economy, Law of Demand, Insensitivity of market budget shares.

Behavioral Heterogeneity in Large Economies

Grandmont\'s ([14]) notion of behavioral heterogeneity is reformulated in a non parametric set-up such that the space of budget share functions admits a ``uniform\'\' probability distribution. If the population is distributed according to this measure, the aggregate budget share function is constant with respect to changes in prices and income. This exact insensitivity of the market budget share function is known to imply uniqueness and global stability of any competitive equilibrium. Here, it is not explained by any insensitivity property at the micro-economic level, but rather by a perfect \'balancing effect\'\'. Eventually, it is proved that the insensitivity property holds approximately for a finite population sufficiently close to, but distinct from, the perfectly heterogenous one.Aggregation of demand, behavioral heterogeneity, large economy, Law of Demand, Insensitivity of market budget shares.

The Exact Insensitivity of Market Budget Shares and the "Balancing Effect"

We reformulate Grandmont's and its successors' notion of behavioral heterogeneity such as to get the exact insensitivity of the aggregate budget share function with respect to changes in prices and income, instead of a mere approximate insensitivity. We propose a non parametric set-up such that, if the population is distributed according to some "uniform" probability measure, the aggregate budget share function is constant. The important contribution is that this exact insensitivity is not explained by any insensitivity at the microeconomic level but rather by an exact "balancing effect". We give illustrative examples of populations that fulfill our requirements.Aggregation of demand, behavioral heterogeneity, balancing effect, large economy, Law of demand.

Preparation of aqueous dispersion of thermoplastic sizing agent for carbon fiber by emulsion/solvent evaporation

In this work, different sizing agent aqueous dispersions based on polyetherimide (PEI) were elaborated in order to improve the interface between carbon fibers and a thermoplastic matrix (PEEK). The dispersions were obtained by the emulsion/solvent evaporation technique. To optimize the stability and the film formation on the fibers, two surfactants were tested at different concentrations, with different concentrations of PEI. The dispersions obtained were characterized by dynamic light scattering (DLS) and the stability evaluated by analytical centrifugation (LUMiFuge). The selected dispersions were tested for film formation ability by scanning electron microscopy (SEM), and the sizing performance was assessed by observation of the fiber/matrix interface by SEM. The results revealed that an aqueous dispersion of PEI,stabilized by sodium dodecyl sulfate as the surfactant, led to very stable sizing agent aqueous dispersion with ideal film formation and better interface adhesion

The Exact Insensitivity of Market Budget Shares and the "Balancing Effect"

URL des Documents de travail : https://centredeconomiesorbonne.cnrs.fr/publications/Document de travail du Centre d'Economie de la Sorbonne n°2007.23 - ISSN : 1955-611XInternational audienceWe reformulate Grandmont's and its successors' notion of behavioral heterogeneity such as to get the exact insensitivity of the aggregate budget share function with respect to changes in prices and income, instead of a mere approximate insensitivity. We propose a non parametric set-up such that, if the population is distributed according to some "uniform" probability measure, the aggregate budget share function is constant. The important contribution is that this exact insensitivity is not explained by any insensitivity at the microeconomic level but rather by an exact "balancing effect". We give illustrative examples of populations that fulfill our requirements.Ce papier propose une reformulation de la notion d'hétérogénéité de comportement forgée par Grandmont et ses successeurs de manière à obtenir l'insensibilité exacte de la fonction de part de budget agrégée à l'égard des modifications de prix et de revenu au lieu d'une simple insensibilité approchée. Pour cela, nous proposons un paradigme non-paramétrique tel que, si la population est distribuée selon une probabilité uniforme, la fonction de part de budget agrégée est constante. La contribution de cette approche est qu'elle n'explique pas l'insensibilité macro-économique par une quelconque homogénéité micro-économique, mais plutôt par un effet de "balancement" exact. Des exemples illustrent notre reformulation

Film formation analysis by diffusive wave spectroscopy

The thin layer analysis is very important for several sectors of industry. Indeed, environmental laws and improvement of performances lead the manufacturers to innovate in the field of coatings and paints. Several classical techniques of characterization (TGA, DMA, etc.) used with this intention do not allow to perform the analysis in situ and are often long and tedious to set up. We propose to solve this problem with a newoptical process. Its technology based on multi-speckle diffusivewave spectroscopy (MS-DWS) allows making real-time analysis in a non-destructive way thanks to an optical measurement. The aim of this work is to highlight correlations between this new technology and the classical methods of analysis. Two film forming polymeric materials were studied, a polydimethylsiloxane (PDMS) and a commercial paint based on an aqueous dispersion of acrylic copolymers. The PDMSwas chosen for the simplicity of its film forming process and is used as model. The paint having a more complex drying mechanism enables to complete this study

The demand for money in developing countries: Assessing the role of financial innovation

Traditional specifications of money demand have been commonly plagU4:!d by persistent overprediction, implausible parameter estimates, and highly autocorrelated errors. This paper argues that some of those problems stem from the failure to account for the impact of financial innovation. We estimate money demand for ten developing countries employing various proxies for the innovation process and provide an assessment of the relative importance of this variable. We find that financial innovation plays an important role in determining money demand and its fluctuations, and that the importance of this role increases with the rate of inflation.