An Inflation Forecasting Model for the Euro Area.

With the European economic integration, the understanding of inflation and inflationary pressures requires to analyse both the national level and the whole Euro area level. This is true in particular for the inflation forecasts that are carried out within the Eurosystem and published four times a year in the ECB Monthly Bulletin. For that purpose, the Banque de France is currently building tools for the Euro area in addition to those already in use for France. The present study puts forward a simple model of short-term developments (one year ahead) in inflation, as measured by the Harmonized Index of Consumer Prices (HICP) of the Euro area. This model does not take into account the feed-back effect of prices on activity, which should be considered in order to analyse medium-term price developments. It could hence be improved along these lines in the future. The model includes seven equations, explaining the total HICP of the Euro area and some of its sector-based sub-indexes (services, manufacturing sector, unprocessed food, processed food, energy and underlying inflation, defined as HICP inflation excluding unprocessed food and energy prices). It uses exogenous variables such as unit labour cost, import deflator, indicators of tightening in the labour market, or in the goods market, and indirect tax indicators. We have favoured an empirical approach rather than a strict compliance with theoretical models, paying particularly attention to the fit of the equations to the data. However, this model is able to provide relevant economic interpretations of recent price developments. Finally, we assess the forecasting performance of the model in traditional in-sample and out-of-sample rolling event evaluations. To do so, the forecasts were compared to the ones obtained from simple autoregressive equations, which are also commonly used to forecast short-term price developments. On the whole, the model provides more accurate forecasts than those provided by the autoregressive model, and a sector-based disaggregated approach outperforms a single equation to forecast total HICP. Part of this result may come from dummy variables that correspond to well identified shocks that improve both the econometric characteristics and forecast performance of the equations of our model.Inflation ; Economic Modelling ; Forecast.

How a Museum Exhibit Functions as a Literacy Event for Viewers

The purpose of this study was to investigate museum learning by describing the experiences of selected museum visitors who viewed a specified exhibit. The research question is: How does a museum exhibit function as a literacy event for viewers? The responses to interview questions described what viewing was like for two subjects. The paradigm for this research is New Literacy Studies (NLS). NLS considers the cultural issues surrounding literacy experiences. NLS assumes that language arts reflect cultural differences and literacy involves the process of constructing meaning (Barton, Hamilton, & Ivanic, 2000; Gee, 2000; Street, 1995). This model of literacy considers three factors of literacy: the literacy practice, the literacy event and the text (Barton & Hamilton, 2000). The literacy practice for this dissertation was museum visiting. The literacy event was viewing one museum exhibit. Through research in multiliteracies (Cope & Kalantzis, 2000), objects and written discourse constituted the text. Two high school subjects spent 15 minutes viewing a specified exhibit on separate occasions. They were asked seven questions designed to aid their recall. The Contextual Model of Learning (Falk & Dierking, 2000) was used for describing the phenomenon and for the analyses of the data. The Contextual Model of Learning describes museum learning as the interaction of three spheres: the Physical Context, the Personal Context, and the Socio-cultural Context. The Physical Context was analyzed through narrative description, the Personal Context through micro-analysis (Corbin, 1998; Miles & Huberman, 1994), and the Socio-cultural Context through Critical Discourse Analysis (Fairclough, 1995; Meyer, 2001; van Dijk, 2001; Wodak, 2001). The results show the Physical Context of a museum exhibit facilitates viewers in accessing their Personal and Socio-cultural Contexts to make meaning. The data indicated the subjects of this study formed global concepts, supported main ideas with specific details, constructed cause and effect relationships, formed comparisons, and engaged in other types of cognitive behaviors as they interacted with the text. The results also indicated that the Contextual Model of Learning would best describe the literacy event if the model showed the dominance of the Personal and Socio-cultural Contexts over the Physical Contents

New constrains on Gliese 86 B

We present the results of multi epochs imaging observations of the companion to the planetary host Gliese 86. Associated to radial velocity measurements, this study aimed at characterizing dynamically the orbital properties and the mass of this companion (here after Gliese 86 B), but also at investigating the possible history of this particular system. We used the adaptive optics instrument NACO at the ESO Very Large Telescope to obtain deep coronographic imaging in order to determine new photometric and astrometric measurements of Gliese 86 B. Part of the orbit is resolved. The photometry of Gliese B indicates colors compatible with a ~70 Jupiter mass brown dwarf or a white dwarf. Both types of objects allow to fit the available, still limited astrometric data. Besides, if we attribute the long term radial velocity residual drift observed for Gliese A to B, then the mass of the latter object is ~0.5 Msun. We analyse both astrometric and radial velocity data to propose first orbital parameters for Gliese B. Assuming Gliese B is a ~0.5 Msun white dwarf, we explore the constraints induced by this hypothesis and refine the parameters of the system.Comment: 10 pages, 18 figures, accepted in A&

Deep search for companions to probable young brown dwarfs

We have obtained high contrast images of four nearby, faint, and very low mass objects 2MASSJ04351455-1414468, SDSSJ044337.61+000205.1, 2MASSJ06085283-2753583 and 2MASSJ06524851-5741376 (here after 2MASS0435-14, SDSS0443+00, 2MASS0608-27 and 2MASS0652-57), identified in the field as probable isolated young brown dwarfs. Our goal was to search for binary companions down to the planetary mass regime. We used the NAOS-CONICA adaptive optics instrument (NACO) and its unique capability to sense the wavefront in the near-infrared to acquire sharp images of the four systems in Ks, with a field of view of 28"*28". Additional J and L' imaging and follow-up observations at a second epoch were obtained for 2MASS0652-57. With a typical contrast DKs= 4.0-7.0 mag, our observations are sensitive down to the planetary mass regime considering a minimum age of 10 to 120 Myr for these systems. No additional point sources are detected in the environment of 2MASS0435-14, SDSS0443+00 and 2MASS0608-27 between 0.1-12" (i.e about 2 to 250 AU at 20 pc). 2MASS0652-57 is resolved as a \sim230 mas binary. Follow-up observations reject a background contaminate, resolve the orbital motion of the pair, and confirm with high confidence that the system is physically bound. The J, Ks and L' photometry suggest a q\sim0.7-0.8 mass ratio binary with a probable semi-major axis of 5-6 AU. Among the four systems, 2MASS0652-57 is probably the less constrained in terms of age determination. Further analysis would be necessary to confirm its youth. It would then be interesting to determine its orbital and physical properties to derive the system's dynamical mass and to test evolutionary model predictions.Comment: Research note, 5 pages, 2 tables and 3 figures, accepted to A&

Near-infrared integral-field spectra of the planet/brown dwarf companion AB Pic b

Chauvin et al. 2005 imaged a co-moving companion at ~260 AU from the young star AB Pic A. Evolutionary models predictions based on J H K photometry of AB Pic b suggested a mass of ~13 - 14 MJup, placing the object at the deuterium-burning boundary. We used the adaptive-optics-fed integral field spectrograph SINFONI to obtain high quality medium-resolution spectra of AB Pic b (R = 1500-2000) over the 1.1 - 2.5 microns range. Our analysis relies on the comparison of our spectra to young standard templates and to the latest libraries of synthetic spectra developed by the Lyon's Group. AB Pic b is confirmed to be a young early-L dwarf companion. We derive a spectral type L0-L1 and find several features indicative of intermediate gravity atmosphere. A comparison to synthetic spectra yields Teff = 2000+100-300 K and log(g) = 4 +- 0.5 dex. The determination of the derived atmospheric parameters of AB Pic b is limited by a non-perfect match of current atmosphere spectra with our near-infrared observations of AB Pic b. The current treatment of dust settling and missing molecular opacity lines in the atmosphere models could be responsible. By combining the observed photometry, the surface fluxes from atmosphere models and the known distance of the system, we derive new mass, luminosity and radius estimates of AB Pic b. They confirm independently the evolutionary model predictions. We finally review the current methods used to characterize planetary mass companions and discuss them in the perspective of future planet deep imaging surveys.Comment: 8 pages, 8 figure

Controlling the charge environment of single quantum dots in a photonic-crystal cavity

We demonstrate that the presence of charge around a semiconductor quantum dot (QD) strongly affects its optical properties and produces non-resonant coupling to the modes of a microcavity. We first show that, besides (multi)exciton lines, a QD generates a spectrally broad emission which efficiently couples to cavity modes. Its temporal dynamics shows that it is related to the Coulomb interaction between the QD (multi)excitons and carriers in the adjacent wetting layer. This mechanism can be suppressed by the application of an electric field, making the QD closer to an ideal two-level system.Comment: 12 pages, 4 figure

Gender Earnings Differentials in Total Pay, Base Pay, and Contingent Pay

Copyright by Cornell University. This is the publisher's version, and is also electronically available from http://ilr.sagepub.com/content/47/4/634.abstract.Using data from a 1988 survey of business school graduates, the authors analyze gender differentials in earnings by form of pay—total pay, base pay, and contingent pay—with controls for human capital, occupation, job level, and individual characteristics. The results indicate that within narrowly defined occupations and jobs, most of the unexplained difference in total pay between the men and women in the sample was due to gender differences in the portion of pay that was contingent on job performance. The greater importance of contingent pay in the earnings of the men than of the women may reflect differential treatment of men and women by firms, gender differences in performance, gender differences in risk preferences, or some other sorting mechanism

Deep infrared imaging of close companions to austral A- and F-type stars

The search for substellar companions around stars with different masses along the main sequence is critical to understand the different processes leading to the formation of low-mass stars, brown dwarfs, and planets. In particular, the existence of a large population of low-mass stars and brown dwarfs physically bound to early-type main-sequence stars could imply that the massive planets recently imaged at wide separations (10-100 AU) around A-type stars are disc-born objects in the low-mass tail of the binary distribution. Our aim is to characterize the environment of early-type main-sequence stars by detecting brown dwarf or low-mass star companions between 10 and 500 AU. High contrast and high angular resolution near-infrared images of a sample of 38 southern A- and F-type stars have been obtained between 2005 and 2009 with the instruments VLT/NaCo and CFHT/PUEO. Multi-epoch observations were performed to discriminate comoving companions from background contaminants. About 41 companion candidates were imaged around 23 stars. Follow-up observations for 83% of these stars allowed us to identify a large number of background contaminants. We report the detection of 7 low-mass stars with masses between 0.1 and 0.8 Msun in 6 multiple systems: the discovery of a M2 companion around the A5V star HD14943 and the detection of the B component of the F4V star HD41742 quadruple system; we resolve the known companion of the F6.5V star HD49095 as a short-period binary system composed by 2 M/L dwarfs. We also resolve the companions to the astrometric binaries iot Crt (F6.5V) and 26 Oph (F3V), and identify a M3/M4 companion to the F4V star omi Gru, associated with a X-ray source. The global multiplicity fraction measured in our sample of A and F stars is >16%. A parallel velocimetric survey of our stars let us conclude that the imaged companions can impact on the observed radial velocity measurements.Comment: 21 pages, 12 figures, 7 tables. Accepted for publication in Astronomy and Astrophysics. The full version of the preprint including the appendices (24 pages of figures), can be retrieved at http://www-laog.obs.ujf-grenoble.fr/~dehrenre/articles/afsurvey