Democratization’s Risk Premium: Partisan and Opportunistic Political Business Cycle Effects on Sovereign Ratings in Developing Countries

We use partisan and opportunistic political business cycle (“PBC”) considerations to develop a framework for explaining election-period decisions by credit rating agencies (“agencies”) publishing developing country sovereign risk-ratings (“ratings”). We test six hypotheses derived from the framework with 482 agency ratings for 19 countries holding 39 presidential elections from 1987-2000. We find that ratings are linked to the partisan orientation of incumbents facing election and to expectations of incumbent victory. Consistent with the framework, rating effects are sometimes greater for right-wing compared to left-wing incumbents, perhaps, because partisan PBC considerations with right-wing (left-wing) incumbents reinforce (counteract) opportunistic PBC considerations.http://deepblue.lib.umich.edu/bitstream/2027.42/39931/3/wp546.pd

DEMOCRACY’S SPREAD: Elections and Sovereign Debt in Developing Countries

We use partisan and opportunistic political business cycle (“PBC”) considerations to develop and test a framework for explaining election-period changes in credit spreads for developing country sovereign bonds. Pre-election bond spread trends are significantly linked both to the partisan orientation of incumbents facing election and to expectations of incumbent victory. Bond spreads for right-wing (leftwing) incumbents increase (decrease) as the likelihood of left-wing (right-wing) challenger victory increases. For right-wing incumbent partisan and opportunistic PBC effects bondholder risk perceptions are mutually reinforcing. For left-wing incumbents partisan PBC effects dominate bondholder risk perceptions compared to opportunistic PBC effects.http://deepblue.lib.umich.edu/bitstream/2027.42/39961/3/wp575.pd

Exploring the spin-1/2 frustrated square lattice model with high-field magnetization measurements

We report on high-field magnetization measurements for a number of layered vanadium phosphates that were recently recognized as spin-1/2 frustrated square lattice compounds with ferromagnetic nearest-neighbor couplings (J_1) and antiferromagnetic next-nearest-neighbor couplings (J_2). The saturation fields of the materials lie in the range from 4 to 24 T and show excellent agreement with the previous estimates of the exchange couplings deduced from low-field thermodynamic measurements. The consistency of the high-field data with the regular frustrated square lattice model provides experimental evidence for a weak impact of spatial anisotropy on the nearest-neighbor couplings in layered vanadium phosphates. The variation of the J_2/J_1 ratio within the compound family facilitates the experimental access to the evolution of the magnetization curve upon the change of the frustration magnitude. Our results support the recent theoretical prediction by Thalmeier et al. [Phys. Rev. B, 77, 104441 (2008)] and give evidence for the enhanced bending of the magnetization curves due to the increasing frustration of the underlying spin system.Comment: Brief Report: 4 pages, 3 figures, 1 tabl

TRAFFIC SAFETY AND ENVIRONMENT

Our transport system is not on a sustainable path. Achievements in terms of mobility have come at some considerable environmental, economic and social cost. Sustainability is a long-term concept, also demanding attention to its social dimension. For transport, this underscores a need to link considerations of the environment and traffic safety together. An integrated strategy implies systematic translation of a broad field of goals into a set of mutually reinforcing packages of measures. The focus is on improving the manner in which different actors recognise the need for co-operation and their readiness to implement it. The starting point is in improving communication. There are clear benefits in integration, in regard of both the synergy of actions as well as improved optimisation, but integration may also bring problems. This article is based on an international survey of an expert group formed by the OECD to review the issues and opportunities of integrating environmental and traffic safety strategies. The group assessed case studies from 12 countries and the European Union, using a classification scheme focusing on the decision contexts and life stages represented by the cases. The group's full report was published in 1997. In its conclusions, the group presents a pragmatic way ahead, and identifies some basic research needs. There are some important persisting questions: how to influence transport demand, how to increase the role of non-motorised traffic and public transport, how to find packages of measures relevant for entire regions surrounding large urban areas, and how to respond to the process of rapid motorisation in developing countries. There are as yet few measures dealing effectively with these issues, or taking them up with a concern for both safety and environment. While the approaches that have shown some success underline the importance of tailoring policies and strategies to the concrete situation of each country, they also demonstrate the importance of the international exchange of know-how. Document type: Articl

Tuning the structural instability of SrTiO_3 by Eu doping: The phase diagram of Sr_1-xEu_xTiO_3

The phase diagram of Sr_1-xEu_xTiO_3 is determined experimentally by electron paramagnetic resonance and resistivity measurements and analyzed theoretically within the self-consistent phonon approximation as a function of x ([0.03-1.0]). The transition temperature of the structural instability of the system increases nonlinearly to higher temperatures with increasing x. This is interpreted theoretically by a substantial alteration in the dynamics caused by a change in the double-well potential from broad and shallow to narrow and deep.Comment: 15 pages, 5 figure

Cauchy-perturbative matching revisited: tests in spherical symmetry

During the last few years progress has been made on several fronts making it possible to revisit Cauchy-perturbative matching (CPM) in numerical relativity in a more robust and accurate way. This paper is the first in a series where we plan to analyze CPM in the light of these new results. Here we start by testing high-order summation-by-parts operators, penalty boundaries and contraint-preserving boundary conditions applied to CPM in a setting that is simple enough to study all the ingredients in great detail: Einstein's equations in spherical symmetry, describing a black hole coupled to a massless scalar field. We show that with the techniques described above, the errors introduced by Cauchy-perturbative matching are very small, and that very long term and accurate CPM evolutions can be achieved. Our tests include the accretion and ring-down phase of a Schwarzschild black hole with CPM, where we find that the discrete evolution introduces, with a low spatial resolution of \Delta r = M/10, an error of 0.3% after an evolution time of 1,000,000 M. For a black hole of solar mass, this corresponds to approximately 5 s, and is therefore at the lower end of timescales discussed e.g. in the collapsar model of gamma-ray burst engines. (abridged)Comment: 14 pages, 20 figure

Do South-Eastern Arabia's Earliest Extant Copper-Alloy Arrowheads date to the Wadi Suq Period?

Die Untersuchung der prähistorischen metallischen Artefakte Südostarabiens entwickelt sich schnell und fast konvulsiv. Es leidet jedoch an einem Mangel an Forschungs- und Veröffentlichungsstandards und einer Diskussionskultur. Nach heutigem Kenntnisstand argumentieren die Autoren, die frühesten erhaltenen metallischen Pfeilspitzen Südost-Arabiens der Wadi Suq-Zeit zuzuordnen. Die zahlreichen Pfeilspitzen sind ein wichtiger Bestandteil der prähistorischen Fundinventar Südostarabiens, die für die arabische Chronologie insgesamt von wesentlicher Bedeutung ist. Dennoch sind die Kontexte des 3. und 2. Jahrtausends unerklärlicherweise frei von metallischen Pfeilspitzen und daher chronologisch verzerrt. Die südostarabische Archäologie muss die Klassifizierung von Artefakten zum Zwecke der Datierung stärker nutzen. Pfeilspitzen, die früher auf die Mitte des 2. Jahrtausends datiert waren, sind jetzt eindeutig teilweise in der frühen Eisenzeit datiert.On current knowledge the authors argue to assign the earliest extant metallic arrowheads of south-eastern Arabia to the Wadi Suq period. Arrowheads are an important component of the south-eastern Arabia's prehistoric find assemblage, integral for chronology on the whole. Nonetheless, 3rd and 2nd millennium contexts are depleted of metallic arrowheads and are chronologically skewed. South-eastern Arabian archaeology must make greater use of artefact classification and typology for the purposes of dating not only to arrowheads, but also in general