Multilateralism versus Regionalism!?

The well-known question whether regional trade agreements (RTAs) and the multilateral trading system (MTS) are "strangers, friends, or foes" (Bhagwati and Panagariya, 1996) has gained new importance with the widespread proliferation of RTAs in recent years. Based on an extensive data set which covers most of world trade over the past 60 years and about 240 regional trade agreements, we analyze the relationship between RTAs and the MTS by combining the gravity model framework with vector auto-regression analysis. Impulse-response-functions robustly suggest that multilateral trade liberalization responds in a signifcantly positive way to regional trade liberalization. We also find robust evidence that RTA liberalization Granger-causes GATT/WTO liberalization. Thus, our results indicate that RTAs do not undermine the MTS but serve as building blocs to multilateral trade liberalization.Regionalism, multilateralism, trade agreement, gravity model

Do the World Trade Organization and the Generalized System of Preferences foster bilateral trade?

World trade has grown exponentially during the last 60 years. Admittedly, it is not clear if this development can be assigned to international trade agreements like the World Trade Organization or the Generalized System of Preferences as previous empirical studies found contradicting results. In this paper we generalize the different approaches used in the lit- erature to estimate the role of GATT/WTO and the Generalized System of Preferences for trade. We use a gravity model and apply FE estimation on a disaggregated bilateral data set of the trade flows between 145 countries across 1962-99. In our analysis we find a significant positive effect of WTO membership on bilateral trade. Referring to other multi- lateral institutions, we find robust evidence that membership in regional trade agreements or currency unions substantially increase bilateral trade flows as well. By contrast, we fi nd that the Generalized System of Preferences does not foster trade in general, rather the opposite. This might be due to the opportunistic behavior of industrial countries that grant GSP schemes as long as the concerned products are relatively unimportant, but restrict them as soon as they become relevant.WTO, GSP, regional trade agreements, currency union, gravity model, international trade

Tetraquark resonances computed with static lattice QCD potentials and scattering theory

We study tetraquark resonances with lattice QCD potentials computed for two static quarks and two dynamical quarks, the Born-Oppenheimer approximation and the emergent wave method of scattering theory. As a proof of concept we focus on systems with isospin $I = 0$, but consider different relative angular momenta $l$ of the heavy $b$ quarks. We compute the phase shifts and search for \mbox{S} and \mbox{T} matrix poles in the second Riemann sheet. We predict a new tetraquark resonance for $l = 1$, decaying into two $B$ mesons, with quantum numbers $I(J^P) = 0(1^-)$, mass $m = 10576_{-4}^{+4} \, \textrm{MeV}$ and decay width $\Gamma = 112_{-103}^{+90} \, \textrm{MeV}$.Comment: 7 pages, 6 figures, 1 table, Proceedings of the 35th International Symposium on Lattice Field Theory, Granada, Spai

The geometry of Hrushovski constructions, I. The uncollapsed case

An intermediate stage in Hrushovski's construction of flat strongly minimal structures in a relational language L produces omega-stable structures of rank omega. We analyze the pregeometries given by forking on the regular type of rank omega in these structures. We show that varying L can affect the (local) isomorphism type of the pregeometry, but not its finite subpregeometries. A sequel will compare these to the pregeometries of the strongly minimal structures.Comment: 31 page

Positive feelings at school: on the relationships between students’ character strengths, school-related affect, and school functioning

The present study was designed to examine the relationships between students’ character strengths, school-related affect, positive school functioning (i.e., motivation to learn, interest, and engagement at class), and school achievement following the “engine model of well-being” that is focusing on inputs (e.g., personality traits), processes (e.g., moods, emotions), and outcomes (e.g., engagement, accomplishments) within the context of well-being research. A sample of 196 children completed the Values in Action Inventory of Strengths for Youth, which assesses 24 character strengths, and the PANAS-C that assesses school-related positive and negative affect. Additionally, homeroom teachers rated students’ positive school functioning (i.e., motivation, engagement, and interest at school) and their overall school achievement. The character strengths of zest, love of learning, perseverance, and social intelligence showed the strongest positive correlations with school-related positive affect. Teamwork, hope, self-regulation, and love were substantially negatively correlated with school-related negative affect. Certain character strengths showed positive relationships with positive school functioning and overall school achievement. A path model, testing the “engine model of well-being”, found—additionally to direct effects—indirect relationships between character strengths and positive school functioning (through school-related positive affect), which in turn leads to higher school achievement. The presented findings show character strengths as meaningful resources in the schooling context. Character strengths emerge to be crucial for students to experience school-related positive affect, which in turn supports students’ positive school functioning and their overall school achievement. The results demonstrate the complex interplay between students’ personality traits, affect, school functioning, and achievement at school