336,052 research outputs found
Time Consistency of Fiscal and Monetary Policy: A Solution
No full textThis paper demonstrates how time consistency of the Ramsey policy–the optimal fiscal and monetary policy under commitment–can be achieved. Each government should leave its successor with a unique maturity structure for the nominal and indexed debt, such that the marginal benefit of a surprise inflation exactly balances the marginal cost. Unlike in earlier papers on the topic, the result holds for quite a general Ramsey policy, including time varying polices with positive inflation and positive nominal interest rates. We compare our results with those in Persson, Persson, and Svensson (1987), Calvo and Obstfeld (1990), and Alvarez, Kehoe, and Neumeyer (2004).time consistency; Ramsey policy; surprise inflation
Skånes humlor
No full textArbetet med affischen har gjorts med stöd av Lunds universitet. Ekologen Anna Persson har skrivit informativa texter och Karin Johnson på Biologiska museet har tagit fram humlearter från insektssamlingarna som sedan har illustrerats av Maj Persson, biolog och illustratör. Bilderna visar honan (drottningen) och hanen (drönaren) av varje skånsk humleart
Pseudo-spin-valve with L 10 (111)-oriented FePt fixed layer
No full textRecently we proposed a spin torque oscillator where the fixed layer has its magnetization easy-axis tilted with respect to the film plane to simultaneously achieve zero-field operation and high output power [Y. Zhou, C. L. Zha, S. Bonetti, J. Persson, and J. Åkerman, Appl. Phys. Lett. 92, 262508 (2008)]. Here we take the first step toward the realization of this device and fabricate successfully a pseudo-spin-valve using an L 10 (111)-oriented FePt fixed layer with tilted magnetocrystalline anisotropy. A total magnetoresistance (MR) of 0.86% is experimentally observed for the standard pseudo-spin-valve of the L 10 FePt/Cu/NiFe structure in applied fields up to 1.5 T. While part of the MR may originate from the FePt film alone, the dominating part of MR correlates with switching of the NiFe free layer. © 2009 American Institute of Physics.link_to_subscribed_fulltex
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Fricke S-duality in CHL models
No full textAbstract: We consider four dimensional CHL models with sixteen spacetime supersymmetries obtained from orbifolds of type IIA superstring on K3×T2 by a ZN symmetry acting (possibly) non-geometrically on K3. We show that most of these models (in particular, for geometric symmetries) are self-dual under a weak-strong duality acting on the heterotic axio-dilaton modulus S by a “Fricke involution” S → −1/NS. This is a novel symmetry of CHL models that lies outside of the standard SL(2Z)-symmetry of the parent theory, heterotic strings on T6. For self-dual models this implies that the lattice of purely electric charges is N-modular, i.e. isometric to its dual up to a rescaling of its quadratic form by N. We verify this prediction by determining the lattices of electric and magnetic charges in all relevant examples. We also calculate certain BPS-saturated couplings and verify that they are invariant under the Fricke S-duality. For CHL models that are not self-dual, the strong coupling limit is dual to type IIA compactified on T6/ZN, for some ZN-symmetry preserving half of the spacetime supersymmetries
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
W. K. C. Guthrie, Les Grecs et leurs dieux. Traduit de l'anglais par S. M. Guillemin
No full textNilsson Martin Persson. W. K. C. Guthrie, Les Grecs et leurs dieux. Traduit de l'anglais par S. M. Guillemin. In: L'antiquité classique, Tome 25, fasc. 2, 1956. pp. 535-536
Utvecklingspedagogik - ett sätt att arbeta både målmedvetet och med barns perspektiv. B. Riddarsporre & S. Persson (red.)
No full textAn interview with Lars-Erik Persson
No full textOn the occasion of his 65th birthday, we had an interview with Professor Lars-Erik Persson. We present several questions in this interview together with his answers. Some of the answers are indeed surprising also to us who know him wellValiderad; 2010; 20100509 (ysko)</p
Which Democracies Pay Higher Wages?
No full textThis paper asks if and how constitutions affect labour market outcomes. This question is motivated by Rodrik (1999), who suggests that 'democracies pay higher wages' and Persson and Tabellini (2003) who provide evidence that constitutions impact on economic outcomes. An empirical analysis using treatment effect estimators and Bayesian Model Averaging provides robust causal evidence that presidential democracies are associated with lower wages, after controlling for other potential determinants such as the level of income per capita.Democracy, Constitutions, Wages, Factor Shares, Bayesian Model Averaging
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