What explains the current low rate of employment in the US? While there has been substantial debate over this question in recent years, we believe that considerable added insight can be derived by focusing on changes in the labor market at the turn of the century. In particular, we argue that in about the year 2000, the demand for skill (or, more specifically, for cognitive tasks often associated with high educational skill) underwent a reversal. Many researchers have documented a strong, ongoing increase in the demand for skills in the decades leading up to 2000. In this paper, we document a decline in that demand in the years since 2000, even as the supply of high education workers continues to grow. We go on to show that, in response to this demand reversal, high-skilled workers have moved down the occupational ladder and have begun to perform jobs traditionally performed by lower-skilled workers. This deskilling process, in turn, results in high-skilled workers pushing low-skilled workers even further down the occupational ladder and, to some degree, out of the labor force all together. In order to understand these patterns, we o↵er a simple extension to the standard skill biased technical change model that views cognitive tasks as a stock rather than a flow. We show how such a model can explain the reversal in the data that we present, and o↵ers a novel interpretation of the current employment situation in the US.

A revised catalogue of Galactic supernova remnants (SNRs) is presented, along with some simple statistics of their properties. Six new SNRs have been added to the catalogue since the previous published version from 2014, and six entries have been removed, as they have been identified as H regions, leaving the number of entries in the catalogue at 294. Some simple statistics of the remnants in the catalogue, and the selection effects that apply, are discussed, along with some recently proposed Galactic SNR candidates.

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Our 50 ks Chandra observation of the small radio supernova remnant (SNR) G1.9ϩ0.3 shows a complete shell structure with strong bilateral symmetry, about in diameter. The radio morphology is also shell-like, 100 but only about in diameter, based on observations made in 1985. We attribute the size difference to expansion 84 between 1985 and our Chandra observations of 2007. Expansion is confirmed in comparing radio images from 1985 and 2008. We deduce that G1.9ϩ0.3 is of order 100 years old-the youngest supernova remnant in the Galaxy. Based on a very high absorbing column density of cm , we place G1.9ϩ0.3 near the Galactic 22 Ϫ25.5 # 10 center, at a distance of about 8.5 kpc, where the mean remnant radius would be about 2 pc, and the required expansion speed about 14,000 km s . The X-ray spectrum is featureless and well described by the exponentially Ϫ1 cut off synchrotron model srcut. With the radio flux at 1 GHz fixed at 0.9 Jy, we find a spectral index of 0.65 and a rolloff frequency of Hz. The implied characteristic rolloff electron energy of about 18