Market power and fiscal policy in OECD countries

We compute average mark-ups as a measure of market power throughout time and study their interaction with fiscal policy and macroeconomic variables in a VAR framework. From impulse-response functions the results, with annual data for a set of 14 OECD countries covering the period 1970-2007, show that the mark-up (i) depicts a pro-cyclical behaviour with productivity shocks and (ii) a mildly counter-cyclical behaviour with fiscal spending shocks. We also use a Panel Vector Auto-Regression analysis, increasing the efficiency in the estimations, which confirms the countryspecific results. JEL Classification: D4, E0, E3, H6Fiscal Policy, Mark-up, Panel VAR, VAR

Level, Slope, Curvature of Sovereign Yield Curve and Fiscal Behaviour

We study fiscal behaviour and the sovereign yield curve in the U.S. and Germany in the period 1981:I-2009:IV. The latent factors, level, slope and curvature, obtained with the Kalman filter, are used in a VAR with macro and fiscal variables, controlling for financial stress conditions. In the U.S., fiscal shocks have generated (i) an immediate response of the short-end of the yield curve, associated with the monetary policy reaction, lasting between 6 and 8 quarters, and (ii) an immediate response of the longend of the yield curve, lasting 3 years, with an implied elasticity of about 80% for the government debt ratio shock and about 48% for the budget balance shock. In Germany, fiscal shocks entail no significant reactions of the latent factors and no response of the monetary policy interest rate. In particular, while (i) budget balance shocks created no response from the yield curve shape, (ii) surprise increases in the debt ratio caused some increase in the short-end and the long-end of the yield curve in the following 2nd and 3rd quarters.yield curve, fiscal policy, financial markets.

Public sector debt dynamics in Brazil

1. INTRODUCTION 2. POLICY MIX AND THE PUBLIC-SECTOR NET DEBT 3. SKELETONS IN THE CLOSET, PRIVATIZATION PROCEEDS AND SEIGNIORAGE 4. SIMULATING DEBT DYNAMICS 5. SENSITIVITY ANALYSIS 6. CONCLUDING REMARKS APPENDIX: THE SIMULATION MODEL

Towards an effective use of language to explain light in the museum

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Museum educators play a key role in explaining science in a museum. Verbal language is primarily used to communicate scientific concepts, but the way language shapes the explanations provided has not been investigated. This qualitative study focuses on the explanations about light provided by three museum educators to 8th grade students (13-14 years old), during unstructured visits to a science museum. The visits were audio-recorded and field notes taken. The museum educators’ language was analyzed at a micro-level, through the perspective of Cognitive Linguistics and Conceptual Metaphor theory. The results of this analysis coupled with a multidimensional framework for analysing explanations allowed an understanding on what is explained and how it is explained in the museum by museum educators. Findings show that explanations were descriptive and causal, structured by the use of hybrid lexicon and by conceptual metaphors, whose quality depends on the structural similarity between domains. Furthermore, the explanations based on geometric optics were qualitative and with low level of precision, complexity and abstractness

Observation of Microlensing towards the Galactic Spiral Arms. EROS II 2 year survey

We present the analysis of the light curves of 8.5 million stars observed during two seasons by EROS (Experience de Recherche d'Objets Sombres), in the galactic plane away from the bulge. Three stars have been found that exhibit luminosity variations compatible with gravitational microlensing effects due to unseen objects. The corresponding optical depth, averaged over four directions, is 0.38 (+0.53, -0.15) 10^{-6}. All three candidates have long Einstein radius crossing times ($\sim$ 70 to 100 days). For one of them, the lack of evidence for a parallax or a source size effect enabled us to constrain the lens-source % geometric configuration. Another candidate displays a modulation of the magnification, which is compatible with the lensing of a binary source. The interpretation of the optical depths inferred from these observations is hindered by the imperfect knowledge of the distance to the target stars. Our measurements are compatible with expectations from simple galactic models under reasonable assumptions on the target distances.Comment: 11 pages, 13 figures, accepted by A&A in Aug 9

Certifying the restricted isometry property is hard

This paper is concerned with an important matrix condition in compressed sensing known as the restricted isometry property (RIP). We demonstrate that testing whether a matrix satisfies RIP is NP-hard. As a consequence of our result, it is impossible to efficiently test for RIP provided P \neq NP

The Upper Mantle Geoid for Lithospheric Structure and Dynamics

Geoid anomalies offer crucial information on the internal density structure of the Earth, and thus, on its constitution and dynamic state. In order to interpret geoid undulations in terms of depth, magnitude and lateral extension of density anomalies in the lithosphere and upper mantle, the effects of lower mantle density anomalies need to be removed from the full geoid (thus obtaining the residual “upper mantle geoid”). However, how to achieve this seemingly simple filtering exercise has eluded consensus for decades in the solid Earth community. While there is wide agreement regarding the causative masses of degrees &gt;10 in spherical harmonic expansions of the upper mantle geoid, those contributing to degrees &lt;7–8 remain ambiguous. Here we use spherical harmonic analysis and recent tomography and density models from joint seismic-geodynamic inversions to derive a representative upper mantle geoid, including the contributions from low harmonic degrees. We show that the upper mantle geoid contains important contributions from degrees 5 and 6 and interpret the causative masses as arising from the coupling between the long-wavelength lithospheric structure and the sublithospheric upper mantle convection pattern. Importantly, the contributions from degrees 3 &lt; l &lt; 8 do not show a simple power-law behavior (e.g., Kaula's rule), which precludes the use of standard filtering techniques in the spectral domain. Our upper mantle geoid model will be useful in studies of (a) lithospheric structure, (b) dynamic topography and mantle viscosity, (c) lithosphere-asthenosphere interactions and (d) the global stress field within the lithosphere and its associated hazards.</p

Market power and fiscal policy in OECD countries

We compute average mark-ups as a measure of market power throughout time and study their interaction with fiscal policy and macroeconomic variables in a VAR framework. From impulse-response functions the results, with annual data for a set of 14 OECD countries covering the period 1970-2007, show that the mark-up (i) depicts a pro-cyclical behaviour with productivity shocks and (ii) a mildly counter-cyclical behaviour with fiscal spending shocks. We also use a Panel Vector Auto-Regression analysis, increasing the efficiency in the estimations, which confirms the country-specific results