482 research outputs found
Adjusting to Trade Policy: Evidence from U.S. Antidumping Duties on Vietnamese Catfish
In 2003, after claims of dumping, the U.S. imposed heavy tariffs on imports of catfish from Vietnam. As a result, Vietnamese exports of catfish to the U.S. market sharply declined. Using a panel data of Vietnamese households, we explore the responses of catfish producers in the Mekong delta between 2002 and 2004. We study adjustments not only in catfish aquaculture but also in other economic activities. We find that, over this period, the rate of income growth was significantly lower among households relatively more involved in catfish farming in 2002. The source of this slower growth is explained by a relative decline in both catfish income and revenues from other miscellaneous farms activities such as poultry and livestock farming. Households did not adjust labor supply, most likely because of off-farm employment limitations. We also document that households more exposed to the shock reduced the share of investment assigned to catfish, while substituting into agriculture.
Adjusting to trade-policy changes in export markets : evidence from U.S. antidumping duties on Vietnamese catfish
A large literature studies the effects of trade policy changes on developing-country exports on household incomes, and recent contributions have increasingly addressed the effects of administered protection, such as anti-dumping duties. In 2003 the United States imposed anti-dumping tariffs on imports of catfish from Vietnam ranging from 37 to 64 percent. As a result, Vietnamese exports of catfish to the U.S. market declined sharply, thus providing a unique opportunity to study the effects of U.S. trade policy changes on Vietnamese families. Using data on Vietnamese households, the authors study the responses of catfish producers in the Mekong delta of Vietnam between 2002 and 2004. The evidence suggests that the rate of growth of income of households that depended on catfish sales was significantly affected. In addition, the anti-dumping duties triggered significant exit from catfish farming. Households adjusted by moving out of catfish aquaculture and into wage labor markets and agriculture, but not into other aquaculture activities. Finally, the evidence also suggests that households found it difficult to change their catfish production levels, and that performance in aquaculture affects other household economic activities.Economic Theory&Research,Fisheries&Aquaculture,Emerging Markets,Wildlife Resources,Labor Policies
Terahertz optically tunable dielectric metamaterials without microfabrication
We theoretically investigate the terahertz dielectric response of a
semiconductor slab hosting an infrared photoinduced grating. The periodic
structure is due to the charge carries photo-excited by the interference of two
tilted infrared plane waves so that the grating depth and period can be tuned
by modifying the beam intensities and incidence angles, respectively. In the
case where the grating period is much smaller than the terahertz wavelength, we
numerically evaluate the ordinary and extraordinary component of the effective
permittivity tensor by resorting to electromagnetic full-wave simulation
coupled to the dynamics of charge carries excited by infrared radiation. We
show that the photoinduced metamaterial optical response can be tailored by
varying the grating and it ranges from birefringent to hyperbolic to
anisotropic negative dielectric without resorting to microfabrication.Comment: 3 pages, 2 figure
Extrinsic electromagnetic chirality in all-photodesigned one-dimensional THz metamaterials
We suggest that all-photodesigned metamaterials, sub-wavelength custom
patterns of photo-excited carriers on a semiconductor, can display an exotic
extrinsic electromagnetic chirality in terahertz (THz) frequency range. We
consider a photo-induced pattern exhibiting 1D geometrical chirality, i.e. its
mirror image can not be superposed onto itself by translations without
rotations and, in the long wavelength limit, we evaluate its bianisotropic
response. The photo-induced extrinsic chirality turns out to be fully
reconfigurable by recasting the optical illumination which supports the
photo-excited carriers. The all-photodesigning technique represents a feasible,
easy and powerful method for achieving effective matter functionalization and,
combined with the chiral asymmetry, it could be the platform for a new
generation of reconfigurable devices for THz wave polarization manipulation.Comment: 11 page
Adjusting to trade policy: Evidence from U.S. antidumping duties on Vietnamese catfish
In 2003, after claims of dumping, the United States imposed heavy tariffs on Vietnamese catfish, which led to a collapse of imports. We use panel data to explore household responses in the catfish-producing Mekong delta between 2002 and 2004 and find that income growth was significantly slower among households relatively more involved in catfish farming in 2002. This is explained by a relative decline in both catfish income and revenues from other miscellaneous farm activities. Labor supply did not adjust, most likely because of off-farm employment limitations. Households more exposed to the shock reduced the share of investment assigned to catfish while substituting into agriculture.Facultad de Ciencias Económica
A Constraint Programming Approach to Automatic Layout Definition for Search Results
In this paper we describe a general framework based on constraint programming techniques to address the automatic layout definition problem for Web search result pages, considering heterogeneous result items types (e.g., web links, images, videos, maps, etc.). Starting from the entity type(s) specified in the search query and the result types deemed more relevant for the given entity type, we define an optimization problem and a set of constraints that grant the optimal positioning of results in the page, modeled as a grid with assigned weights depending on the visibility
Measurement of heavy-flavour production in proton-proton collisions at sqrt{s} = 7 TeV with ALICE
The measurement of the heavy-flavour production cross sections in pp
collisions at the LHC will allow to test perturbative QCD calculations in a new
energy domain. Moreover, within the physics program of the ALICE experiment, it
will provide the reference for the study of medium effects in Pb-Pb collisions,
where heavy quarks are regarded as sensitive probes of parton-medium
interaction dynamics. We present the status and first preliminary results of
charm and beauty production measurements with the ALICE experiment, using
hadronic D meson decays and semi-leptonic D and B meson decays, including the
first cross section measurement of muons from heavy flavour decays at forward
rapidity. We also describe the preliminary cross section measurement for J/psi
production, obtained using the di-electron decay channel at central rapidity
and the di-muon decay channel at forward rapidity.Comment: 8 pages, 5 figures, proceedings of the conference HARD PROBES 2010,
Eilat, October 201
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