Moody’s Ratings Statistical Forecasting for Industrial and Retail Firms

Long-term ratings of companies are obtained from public data plus some additional nondisclosed information. A model based on data from firms’ public accounts is proposed to directly obtain these ratings, showing fairly close similitude with published results from Credit Rating Agencies. The rating models used to assess the creditworthiness of a firm may involve some possible conflicts of interest, as companies pay for most of the rating process and are, thus, clients of the rating firms. Such loss of faith among investors and criticism toward the rating agencies were especially severe during the financial crisis in 2008. To overcome this issue, several alternatives are addressed; in particular, the focus is on elaborating a rating model for Moody’s long-term companies’ ratings for industrial and retailing firms that could be useful as an external check of published rates. Statistical and artificial intelligence methods are used to obtain direct prediction of awarded rates in these sectors, without aggregating adjacent classes, which is usual in previous literature. This approach achieves an easy-to-replicate methodology for real rating forecasts based only on public available data, without incurring the costs associated with the rating process, while achieving a higher accuracy. With additional sampling information, these models can be extended to other sectors.

Systematics and accuracy of VLBI astrometry: A comparison with Gaia Data Release 2

Context. The third generation of the ICRF – ICRF3 – was published in 2018. This new fundamental catalog provides radio source positions measured independently at three bands: S/X, K, and X/Ka, representing three independent radio celestial frames which altogether constitute a multi-frequency ICRF. Aims. We aim to investigate the overall properties of the ICRF3 with the help of the Gaia Data Release 2 (Gaia DR2). This could serve as an external check of the quality of the ICRF3. Methods. The radio source positions of the ICRF3 catalog were compared with the Gaia DR2 positions of their optical counterparts at G < 18.7. Their properties were analyzed in terms of the dependency of the quoted error on the number of observations, on the declination, and the global difference, the latter revealed by means of expansions in the vector spherical harmonics. Results. The ICRF3 S/X-band catalog shows a more smooth dependency on the number of observations than the ICRF1 and ICRF2, while the K and X/Ka-band yield a dependency discrepancy at the number of observations of ∼50. The rotation of all ICRF catalogs show consistent results, except for the X-component of the X/Ka-band which arises from the positional error in the non-defining sources. No significant glides were found between the ICRF3 S/X-band component and Gaia DR2. However, the K- and X/Ka-band frames show a dipolar deformation in Y-component of +50 μas and several quadrupolar terms of 50 μas in an absolute sense. A significant glide along Z-axis exceeding 200 μas in the X/Ka-band was also reported. These systematics in the ICRF catalog are shown to be less dependent on the limiting magnitude of the Gaia sample when the number of common sources is sufficient (>100). Conclusions. The ICRF3 S/X-band catalog shows improved accuracy and systematics at the level of noise floor. But the zonal errors in the X/Ka-band should be noted, especially in the context of comparisons of multi-frequency positions for individual sources.

Constraining the Formation and Mass of the Milky Way Halo using Globular Cluster Orbits from HST Proper Motions

The globular cluster (GC) system of the Milky Way (MW) provides important information on the MW’s present structure and past evolution. Full 3d motions, accessed through proper motions (PMs), are required to calculate accurate orbits of GCs in the MW halo. We present our HST program to create a PM database for 20 halo GCs. We demonstrate how the observed PMs of individual GCs can be used to study their origins, and we also describe how the PM measurements of our entire targets can be used to constrain the anisotropy profile. Finally, we describe how our PM results can be used for Gaia as an external check, and discuss prospects of PM measurements with HST and Gaia in the coming years.

HST Proper Motions of Distant Globular Clusters: Constraining the Formation & Mass of the Milky Way

Proper motions (PMs) are required to calculate accurate orbits of globular clusters (GCs) in the Milky Way (MW) halo. We present our HST program to create a PM database for 20 GCs at distances of RGC = 10–100 kpc. Targets are discussed along with PM measurement methods. We also describe how our PM results can be used for Gaia as an external check, and discuss the synergy between HST and Gaia as astrometric instruments in the coming years.

Beyond Refusal to Deal: A Cross-Atlantic View of Copyright, Competition and Innovation Policies

Conventional wisdom holds that the European Union has opted to apply its competition law to the exercise of intellectual property rights to a much greater extent than has the United States. We argue that, at least in the context of copyright protection, this conventional wisdom is false. While European antitrust regulation of refusal to license one's intellectual property does seem much more robust and activist than U.S. antitrust regulation of similar conduct, focusing solely on one narrow aspect of antitrust doctrine — the treatment of a unilateral refusal to deal — tells less than half the story.Once various doctrines of copyright law are taken into account, the substantive difference between the European and American approaches not only narrows, but in some key respects is reversed. While European jurisdictions have relatively expansive copyright protection which may require antitrust intervention to check anti-competitive uses of copyrighted works, American copyright law provides stronger internal limits on copyright protection, which thereby lessens the need for resort to antitrust law as an external check on anti-competitive uses of copyrighted works. Furthermore, when the broader impact that antitrust law might have on the exercise of IPRs in the United States is considered (not only in substance, but also in antitrust process), it becomes apparent that in key respects, when innovative-competition is at stake, U.S. law grants overall weaker copyright protection than that available in Europe. We also explain why the two jurisdictions have adopted distinct approaches to resolving similar problems and evaluate those approaches.

A Test of the Astrometric Quality of the Southern Guide Star Catalog 1.2

We used preliminary positions of the Yale Southern Proper Motion (SPM) catalogue (Platais, Girard et al., Astronomy from Large Database II, eds. Heck & Murtag, 1992) in a region of 5 fields around the South Galactic Pole to assess the astrometric accuracy of the mask solution (Taff, Lattanzi and Bucciarelli, ApJ 361, 667, 1990), which will be used (in combination with the subplate method) for the construction of the Guide Star Catalogue (GSC) version 1.2. Another semi-external check is done by direct comparison of GSC positions of stars lying onto overlapping plate areas. Results in tables 1 and 2 show that the average rms of the GSC–SPM differences is quite satisfactory (∼ 0.33 arcsecper coordinate), while an error degradation (up to ∼ 1 arcsecpositional) can occurr within a limited area at the plate corners, its signature varying from plate to plate. This can be cured on a plate-by-plate basis by the use of a filtering technique, e.g., as provided by the Collocation method (Bucciarelli, Lattanzi and Taff, ApJ Suppl. 84, 91, 1993), wherever a suitable reference star density is available.

Que pourra-t-on deduire des mesures de distance terre-lune par laser?

Although several lunar laser ranging stations exist, only one is now fully operational: the McDonald station with internal observational errors of less than 15 cm. The interpretation of the data involves a great number of parameters relative to the Earth and the Moon which are listed.The lunar laser is particularly fit for those parameters that pertain to the Moon, and with future lasers accurate to 2 or 3 cm, it may be expected that this accuracy will be projected into these parameters. The probable determination of the semi-major axis to 1 cm accuracy for a few months mean would imply a new means of determining the non conservative part of the motion of the Moon. A similar precision is to be expected for the rotation of the Moon. The situation for the Earth parameters (Earth rotation and polar motion) is not so good, because of a rather weak geometry of the problem and the monthly one week gap in the observations. Nevertheless, it will give a very useful external check on other competing methods (radio-interferometry, laser or radio-satellites).