2,977 research outputs found
The Customs Union Issue: Why do we Observe so few of them?
The number of preferential trade agreements has greatly increased over the past two decades, yet most existing bilateral arrangements take the form of free trade areas, and less than ten percent can be considered to be fully fledged customs unions. This paper develops a political economy model of trade policy under imperfect competition to provide a positive explanation for the prevalence of free trade areas. In a three-country setting, a representative from each prospective member is elected to determine the tariffs to be applied on imported goods. Under a customs union, the necessity to coordinate tariffs leads voters to strategically delegate power to more protectionist representatives. Contrary to most of the existing literature, we show that strategic delegation may imply that free trade areas increase welfare compared to customs unions. Moreover, the model also indicates that free trade areas are more likely to be politically viable than customs unions.strategic delegation, preferential trade agreements
Export Growth and Factor Market Competition: Theory and Evidence
Empirical evidence suggests that sectoral export growth decreases exporters\' survival probability, whereas non{exporters are unaffected. Models with firm heterogeneity in total factor productivity predict the opposite. To solve this puzzle, we develop a two-factor framework where firms differ in factor shares. In this model, export growth increases competition for the factor used intensively by exporters, eliminating some of them, while non-exporters benefit. Our empirical analysis shows that the forces highlighted in the model drive the firm selection experienced by the Chilean manufacturing sector, suggesting that heterogeneity in factor shares is crucial to understand how firms react to trade liberalization.Firm Dynamics, Two-Factor Trade Model, Firm Heterogeneity in Factor Shares, Chile, Manufacturing Industry
Experimental study of vapor-cell magneto-optical traps for efficient trapping of radioactive atoms
We have studied magneto-optical traps (MOTs) for efficient on-line trapping
of radioactive atoms. After discussing a model of the trapping process in a
vapor cell and its efficiency, we present the results of detailed experimental
studies on Rb MOTs. Three spherical cells of different sizes were used. These
cells can be easily replaced, while keeping the rest of the apparatus
unchanged: atomic sources, vacuum conditions, magnetic field gradients, sizes
and power of the laser beams, detection system. By direct comparison, we find
that the trapping efficiency only weakly depends on the MOT cell size. It is
also found that the trapping efficiency of the MOT with the smallest cell,
whose diameter is equal to the diameter of the trapping beams, is about 40%
smaller than the efficiency of larger cells. Furthermore, we also demonstrate
the importance of two factors: a long coated tube at the entrance of the MOT
cell, used instead of a diaphragm; and the passivation with an alkali vapor of
the coating on the cell walls, in order to minimize the losses of trappable
atoms. These results guided us in the construction of an efficient
large-diameter cell, which has been successfully employed for on-line trapping
of Fr isotopes at INFN's national laboratories in Legnaro, Italy.Comment: 9 pages, 7 figures, submitted to Eur. Phys. J.
No-signaling, entanglement-breaking, and localizability in bipartite channels
A bipartite quantum channel represents the interaction between systems,
generally allowing for exchange of information. A special class of bipartite
channels are the no-signaling ones, which do not allow communication. In Ref.
[1] it has been conjectured that all no-signaling channels are mixtures of
entanglement-breaking and localizable channels, which require only local
operations and entanglement. Here we provide the general realization scheme,
giving a counterexample to the conjecture.Comment: 4 pages, revtex
Substitutability and Protectionism: Latin America’s Trade Policy and Imports from China and India
This paper examines the trade policy response of Latin American governments to the rapid growth of China and India in world markets. To explain higher protection in sectors where a large share is imported from these countries, we extend the ‘protection for sale’ model to allow for different degrees of substitutability between domestically produced and imported varieties. The extension suggests that higher levels of protection towards Chinese goods can be explained by high substitutability between domestically produced goods and Chinese goods, whereas lower levels of protection towards goods imported from India can be explained by low substitutability with domestically produced goods. The data supports the extension to the ‘protection for sale’ model, which performs better than the original specification in terms of explaining Latin America's structure of protection.Latin America, protectionism
The Modal mu-Calculus and The Gödel-Löb Logic
We show that the modal µ-calculus over GL collapses to the modal fragment by showing that the fixpoint formula is reached after two iterations and answer to a question posed by van Benthem in [vBe06]. Further, we introduce the modal µ∼-calculus by allowing fixpoint constructors for any formula where the fixpoint variable appears guarded but not necessarily positive and show that this calculus over GL collapses to the modal fragment, too. The latter result allows us a new proof of the de Jongh, Sambin Theorem and provides a simple algorithm to construct the fixpoint formula
Arbitrageurs in the Bitcoin ecosystem: Evidence from user-level trading patterns in the Mt. Gox exchange platform
The Modal μ-Calculus Hierarchy on Restricted Classes of Transition Systems
We discuss the strictness of the modal µ-calculus hierarchy over some restricted classes of transition systems. First, we show that the hierarchy is strict over reflexive frames. By proving the finite model theorem for reflexive systems the same results holds for finite models. Second, we prove that over transitive systems the hierarchy collapses to the alternation-free fragment. In order to do this the finite model theorem for transitive transition systems is also proved. Further, we verify that if symmetry is added to transitivity the hierarchy collapses to the purely modal fragment
Optimal quantum tomography for states, measurements, and transformations
We present the first complete optimization of quantum tomography, for states,
POVMs, and various classes of transformations, for arbitrary prior ensemble and
arbitrary representation, giving corresponding feasible experimental schemes.Comment: 4 pages, 1 figur
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