The Growth of Bilateralism

One of the most notable international economic events over the past 20 years has been the proliferation of bilateral free trade agreements (FTAs). Bilateral agreements account for 80 percent of all agreements notified to the WTO, 94 percent of those signed or under negotiation, and currently 100 percent of those at the proposal stage. Some have argued that the growth of bilateralism is attributable to governments having pursued a policy of "competitive liberalization" - implementing bilateral FTAs to offset potential trade diversion caused by FTAs of "third-country-pairs" - but the growth of bilateralism can also be attributed potentially to "tariff complementarity" - the incentive for FTA members to reduce their external tariffs on nonmembers. Guided by new comparative statics from the numerical general equilibrium monopolistic competition model of FTA economic determinants in Baier and Bergstrand (2004), we augment their parsimonious logit (and probit) model of the economic determinants of bilateral FTAs to incorporate theory-motivated indexes to examine the in°uence of existing memberships on subsequent FTA formations. The model can predict correctly 90 percent of the bilateral FTAs within five years of their formation, while still predicting "No-FTA" correctly in 90 percent of the observations when no FTA exists, using a sample of over 350,000 observations for pairings of 146 countries from 1960-2005. Even imposing the higher correct prediction rate of "No-FTA" of 97 percent in Baier and Bergstrand (2004), the parsimonious model still predicts correctly 75 percent of these rare FTA events; only 3 percent of the observations reflect a country-pair having an FTA in any year. The results suggest that while evidence supports that "competitive liberalization" is a force for bilateralism the efect on the likelihood a pair of countries forming an FTA of the pair's own FTAs with other countries (i.e., tariff complementarity) is likely just as important as the effect of third-country-pairs' FTAs (i.e. competitive liberalization) for the growth of bilateralism.Free Trade Agreements; International Trade; Endogenous Tariffs

On the Angular Dependence of the Radiative Gluon Spectrum

The induced momentum spectrum of soft gluons radiated from a high energy quark produced in and propagating through a QCD medium is reexamined in the BDMPS formalism. A mistake in our published work (Physical Review C60 (1999) 064902) is corrected. The correct dependence of the fractional induced loss $R(\theta_{{\rm cone}})$ as a universal function of the variable $\theta^2_{{\rm cone}} L^3 \hat q$ where $L$ is the size of the medium and $\hat q$ the transport coefficient is presented. We add the proof that the radiated gluon momentum spectrum derived in our formalism is equivalent with the one derived in the Zakharov-Wiedemann approach.Comment: LaTex, 5 pages, 1 figur

Coulomb effects in the spin-dependent contribution to the intra-beam scattering rate

Coulomb effects in the intra-beam scattering are taken into account in a way providing correct description of the spin-dependent contribution to the beam loss rate. It allows one to calculate this rate for polarized $e^{\pm}$ beams at arbitrarily small values of the ratio $\delta \varepsilon/\varepsilon$, characterizing relative change of the electron energy in the laboratory system during scattering event.Comment: 8 pages, 2 figure

Do free trade agreements actually increase members’ international trade?

For more than forty years, the gravity equation has been a workhorse for cross-country empirical analyses of international trade flows and, in particular, the effects of free trade agreements (FTAs) on trade flows. However, the gravity equation is subject to the same econometric critique as earlier cross-industry studies of U.S. tariff and nontariff barriers and U.S. multilateral imports: Trade policy is not an exogenous variable. The authors address econometrically the endogeneity of FTAs using instrumental-variable (IV) techniques, control-function (CF) techniques, and panel-data techniques; IV and CF approaches do not adjust for endogeneity well, but a panel-data approach does. Accounting econometrically for the FTA variable’s endogeneity yields striking empirical results: The effect of FTAs on trade flows is quintupled.

Thermocapillary Flow on Superhydrophobic Surfaces

A liquid in Cassie-Baxter state above a structured superhydrophobic surface is ideally suited for surface driven transport due to its large free surface fraction in close contact to a solid. We investigate thermal Marangoni flow over a superhydrophobic array of fins oriented parallel or perpendicular to an applied temperature gradient. In the Stokes limit we derive an analytical expression for the bulk flow velocity above the surface and compare it with numerical solutions of the Navier-Stokes equation. Even for moderate temperature gradients comparatively large flow velocities are induced, suggesting to utilize this principle for microfluidic pumping.Comment: 4 pages, 4 figure

Partonic Energy Loss and the Drell-Yan Process

We examine the current status of the extraction of the rate of partonic energy loss in nuclei from A dependent data. The advantages and difficulties of using the Drell-Yan process to measure the energy loss of a parton traversing a cold nuclear medium are discussed. The prospects of using relatively low energy proton beams for a definitive measurement of partonic energy loss are presented.Comment: 12 pages, 2 figure

Medium-induced gluon radiation and jet quenching in heavy ion collisions

In this brief review, I summarize the new developments on the description of gluon radiation by energetic quarks traversing a medium as well as the observable consequences in high-energy heavy ion collisions. Information about the initial state is essential for a reliable interpretation of the experimental results and will also be reviewed. Comparison with experimental data from RHIC and expectation for the future LHC will be given.Comment: 16 pages, 9 postscript figures. Invited brief review for Modern Physics Letters

Averages of shifted convolutions of d3(n)d_3(n)

We investigate the first and second moments of shifted convolutions of the generalised divisor function $d_3(n)$.Comment: 22 page

Medium-modified fragmentation of b-jets tagged by a leading muon in ultrarelativistic heavy ion collisions

The possibility to observe the medium-modified fragmentation of hard b-quarks tagged by a leading muon in ultrarelativistic heavy ion collisions is analyzed. We have found that reasonable statistics, ~20000 events per 1 month of LHC run with lead beams, can be expected for the realistic geometrical acceptance and kinematic cuts. The numerical estimates on the effect of the medium-induced softening b-jet fragmentation function are given.Comment: 12 pages in LaTeX (including 3 figures in EPS-format