Existence and Uniqueness of Semiparametric Projections

In this paper we propose primitive conditions under which a projec- tion of a conditional density onto a set de#ned by conditional moment restric- tions exists and is unique. Moreover, we provide an analytic expression of the obtained projection. Our #rst result is to show the existence when the moment function is bounded. The result is as we would expect from the analogous results obtained in the unconditional case. Our second result relaxes the boundedness assumption and replaces it with a correct speci#cation condition. Showing that the correct speci#cation of the moment function is su#cient for the projection to exist is entirely new and not yet seen in the literature

What Goods Do Countries Trade? A Quantitative Exploration of Ricardo’s Ideas

The Ricardian model predicts that countries should produce and export relatively more in industries in which they are relatively more productive. Though one of the most celebrated insights in the theory of international trade, this prediction has received little attention in the empirical literature since the mid-1960s. The main reason behind this lack of popularity is the absence of clear theoretical foundations to guide the empirical analysis. Building on the seminal work of Eaton and Kortum (“Technology, Geography, and Trade”, Econometrica, 70, 1741–1779 2002), we offer such foundations and use them to quantify the importance of Ricardian comparative advantage. In the process, we also provide a theoretically consistent alternative to Balassa's (1965, “An Empirical Demonstration of Classical Comparative Cost Theory”, Review of Economics and Statistics, 45, 231–238) well-known index of “revealed comparative advantage”

Existence and Uniqueness of Semiparametric Projections

In this paper we propose primitive conditions under which a projec- tion of a conditional density onto a set de#ned by conditional moment restric- tions exists and is unique. Moreover, we provide an analytic expression of the obtained projection. Our #rst result is to show the existence when the moment function is bounded. The result is as we would expect from the analogous results obtained in the unconditional case. Our second result relaxes the boundedness assumption and replaces it with a correct speci#cation condition. Showing that the correct speci#cation of the moment function is su#cient for the projection to exist is entirely new and not yet seen in the literature

Phosphorylation of Mono- or Di-octadienyl-D-xylosides. Influence towards Surfactant Properties

International audienc

Destabilisation of Water-in-Crude Oil Emulsions by Silicone Copolymer Demulsifiers

Asphaltene aggregates are known to form viscoelastic film preventing the coalescence of droplets in water-in-oil emulsions formed during crude oil exploitation. Since phase separation is necessary for oil refining process, demulsifying additives are used. It was found that formulations based on polysiloxane copolymers promote separation of water from crude oil even at very low concentration (few tens of ppm). Two alternative scenarios of emulsion destabilisation can be envisaged: (i) dissolution of asphaltene aggregates or (ii) displacement of the asphaltene network by adsorption of the more surface active copolymer into void sites at the oil/water interface. In order to reveal the mechanism of destabilisation, interactions between asphaltene aggregates and copolymer were explored. For that purpose various techniques have been employed: small angle X-ray scattering allowing the determination of the influence of copolymer on the size of asphaltene aggregate; capacity of copolymer to displace asphaltene aggregates initially adsorbed on silica particles (which simulate water droplets); Atomic Force Microscopy (AFM) was used to observe the influence of copolymer on the interfacial structure of asphaltene films spread on water surface