The Effect of the Uruguay round on the Intensive and Extensive Margins of Trade

Do tariffs inhibit trade flows by limiting the entry of exporting firms (extensive margin') or by restricting the average volume exported by each firm (intensive margin')? Using a gravity equation approach, we analyze how the decrease in tariffs promoted during the 1990s by the Uruguay Round multilateral trade agreement affected the trade margins of French firms across 57 sectors and in 147 countries, from 1993 to 2002. Our main contribution is to estimate the elasticity of trade for both margins, controlling for the unobserved heterogeneity of trade flows thanks to a three-dimensional panel and to time-varying tariffs as a measure of variable trade costs. Our results show that the number of firms exporting in a given sector to a given destination is related to the level of tariffs. But they also show that the decrease in tariffs determined by the implementation of the Uruguay Round did not lead more firms to export and instead, only encouraged incumbent exporters to increase their shipments. We control for two problems that may affect our basic specification: tariffs changes may be endogenous and zero flows are not included. Our results are confirmed - even when the extensive margin is significant, its contribution is very small.Tariffs, Trade margins, Uruguay Round

Enhanced transmission of slit arrays in an extremely thin metallic film

Horizontal resonances of slit arrays are studied. They can lead to an enhanced transmission that cannot be explained using the single-mode approximation. A new type of cavity resonance is found when the slits are narrow for a wavelength very close to the period. It can be excited for very low thicknesses. Optimization shows these structures could constitute interesting monochromatic filters

The reaction of French firms to the decrase of foreign tariffs

We estimate the reaction of French firms to the drop in tariffs that has occurred in the late 1990s, mainly as a consequence of the Uruguay Round Agreement. To perform this estimation, we use data from the French customs and tariff rates provided by the TRAINS data base. Like in Buono and Lalanne (2009), we take advantage of the variations in tariffs over time. It allows us to exploit the panel structure of the data, which is not possible when using distance instead of tariffs. The results and the estimated reaction of firms to changes in variable export costs are strongly affected. From a cross-section, we find that the effect of tariffs on exports channels evenly through the number of exporting firms - the extensive margin - and through the exports per firm - the intensive margin. When using the panel structure, only the intensive margin reacts to tariff reductions. To understand what underlies this result, we study the role played by incumbent exporters. The latter are responsible for 95 % of the response of French exports to tariff reductions. Finally, we find that firms respond to these lower export costs by increasing their amounts exported by product rather than by exporting new products.Tariffs, Trade margins, Uruguay Round

Photon recycling in Fabry-Perot micro-cavities based on Si3_3N4_4 waveguides

We present a numerical analysis and preliminary experimental results on one-dimensional Fabry-Perot micro-cavities in Si$_3$N$_4$ waveguides. The Fabry-Perot micro-cavities are formed by two distributed Bragg reflectors separated by a straight portion of waveguide. The Bragg reflectors are composed by a few air slits produced within the Si$_3$N$_4$ waveguides. In order to increase the quality factor of the micro-cavities, we have minimized, with a multiparametric optimization tool, the insertion loss of the reflectors by varying the length of their first periods (those facing the cavity). To explain the simulation results the coupling of the fundamental waveguide mode with radiative modes in the Fabry-Perot micro-cavities is needed. This effect is described as a recycling of radiative modes in the waveguide. To support the modelling, preliminary experimental results of micro-cavities in Si$_3$N$_4$ waveguides realized with Focused Ion Beam technique are reported.Comment: 5 pages, 5 figure

Oil price and potential output growth in the long run

The goal of this paper is to gauge the impact of the expected oil price increase on the potential output growth of the French economy in the long run. This potential output exercise is conducted using CES (Constant Elasticity of Substitution) production functions featuring three factors: capital, labour and energy. Moreover, the sectoral composition of the economy is taken into account through a breaking down of the economy into four sectors (manufacturing industry, construction, market services, and agriculture). The model yields a potential output of growth of about 2 % per year in the absence of oil price variations. The various scenarios of oil price increases result in a shortage of growth between 0.1 and 0.6 % per year in the medium run with respect to the constant oil price scenario. The major part of this growth shortage channels through a negative impact on the manufacturing sector, which is highly energy-intensive and also the engine of technical progress.Potential output growth, Unbalanced growth, Oil price

Sharing the fruits of growth from 1950 to 2008: A surplus-accounting approach

In this paper, we apply the surplus accounting methodology to analyze the distribution of the fruits of growth between production factors over the period 1950-2008. Three production factors are distinguished: paid employment, self-employment and capital. The surplus distributed to capital is nil on average. The employees received a surplus linked to the evolution of total factor productivity, which experienced a slowdown in the 1980s Since 2007, the distributed surplus has sharply dropped, due to an increase in external deduction. The evolution of the surplus is, then, confronted to value-added distribution, by focusing on the capital-labour substitution in the 1980s. The standard framework of surplus accounting is, finally, extended by taking the Welfare System and its financing into account. Indeed, even if the Welfare System is mostly financed by social contributions paid by production factors, social benefits are also distributed to agents who are not involved in the production process, namely the pensioners, the unemployed, and the non-working population. We find that the surplus distributed to employees is lower when social contributions are taken into account. In the meantime, a half-percentage point of the value-added growth rate is assigned each year to the financing of the old-age insurance, whose main part however (0.4 point) accrues tothe growing number of new pensioners. Nevertheless, the incomes after social benefits allocated to the employed, the unemployed, and pensioners grow at a similar pace.Surplus Accounting, Value-Added Distribution, Welfare System, Pensioners

Search for proton decay in the Frejus experiment

The status of the Frejus experiment and the preliminary results obtained in the search for nucleon decay are discussed. A modular, fine grain tracking calorimeter was installed in the Frejus laboratory in the period extending from October 1983 to May 1985. The 3300 cubic meter underground laboratory, located in the center of the Frejus tunnel in the Alps, is covered in the vertical direction by 1600 m of rocks (4400 m w.e.). The average number of atmospheric muons in the lab is 4.2 square meters per day. The 912 ton detector is made of 114 modules, each one including eight flash chamber and one Geiger vertical planes of (6 x 6) square meters dimensions. The flash chamber (and Geiger) planes are alternatively crossed to provide a 90 deg. stereo reconstruction. No candidate for the nucleon decay into charged lepton is found in the first sample of events

Enhancement of spatial coherence by surface plasmons

We report on a method to generate a stationary interference pattern from two independent optical sources, each illuminating a single slit in Young's interference experiment. The pattern arises as a result of the action of surface plasmons traveling between subwavelength slits milled in a metal film. The visibility of the interference pattern can be manipulated by tuning the wavelength of one of the optical sources. © 2007 Optical. Society of America

A Fast and Compact Quantum Random Number Generator

We present the realization of a physical quantum random number generator based on the process of splitting a beam of photons on a beam splitter, a quantum mechanical source of true randomness. By utilizing either a beam splitter or a polarizing beam splitter, single photon detectors and high speed electronics the presented devices are capable of generating a binary random signal with an autocorrelation time of 11.8 ns and a continuous stream of random numbers at a rate of 1 Mbit/s. The randomness of the generated signals and numbers is shown by running a series of tests upon data samples. The devices described in this paper are built into compact housings and are simple to operate.Comment: 23 pages, 6 Figs. To appear in Rev. Sci. Inst