•SOHO SWAN obtained 885 images of H Lyman-α 9 dynamically new and long period comets.•Water production rates were calculated for all comets.•Pre- and post-perihelion activity variations were ...characterized for each comet.•Comet C/2014 Q1 (PanSTARRS) showed evidence of massive shedding and sublimation of nucleus material around perihelion.•It is estimated that C/2014 Q1 (PanSTARRS) lost ∼64% of its original mass.
Nine recently discovered long-period comets were observed by the Solar Wind Anisotropies (SWAN) Lyman-alpha all-sky camera on board the Solar and Heliosphere Observatory (SOHO) satellite during the period of 2013 to 2016. These were C/2012 K1 (PanSTARRS), C/2013 US10 (Catalina), C/2013 V5 (Oukaimeden), C/2013 R1 (Lovejoy), C/2014 E2 (Jacques), C/2014 Q2 (Lovejoy), C/2015 G2 (MASTER), C/2014 Q1 (PanSTARRS) and C/2013 XI (PanSTARRS). Of these 9 comets 6 were long-period comets and 3 were possibly dynamically new. Water production rates were calculated from each of the 885 images using our standard time-resolved model that accounts for the whole water photodissociation chain, exothermic velocities and collisional escape of H atoms. For most of these comets there were enough observations over a broad enough range of heliocentric distances to calculate power-law fits to the variation of production rate with heliocentric distances for pre- and post-perihelion portions of the orbits. Comet C/2014 Q1 (PanSTARRS), with a perihelion distance of only ∼0.3 AU, showed the most unusual variation of water production rate with heliocentric distance and the resulting active area variation, indicating that when the comet was within 0.7 AU its activity was dominated by the continuous release of icy grains and chunks, greatly increasing the active sublimation area by more than a factor of 10 beyond what it had at larger heliocentric distances. A possible interpretation suggests that a large fraction of the comet's mass was lost during the apparition.
Monopsony in the US Labor Market Yeh, Chen; Macaluso, Claudia; Hershbein, Brad
The American economic review,
07/2022, Letnik:
112, Številka:
7
Journal Article
Recenzirano
Odprti dostop
This paper quantifies employer market power in US manufacturing and how it has changed over time. Using administrative data, we estimate plant-level markdowns—the ratio between a plant’s marginal ...revenue product of labor and its wage. We find most manufacturing plants operate in a monopsonistic environment, with an average markdown of 1.53, implying a worker earning only 65 cents on the marginal dollar generated. To investigate long-term trends for the entire sector, we propose a novel, theoretically grounded measure for the aggregate markdown. We find that it decreased between the late 1970s and the early 2000s, but has been sharply increasing since. (JEL J24, J31, J38, J42, L13, L60)
This book presents a sociocultural linguistic analysis of discourses of conflict, as well as an examination of how linguistic identity is embodied, negotiated and realized during a time of war. It ...provides new insights regarding multilingualism among Ukrainians in Ukraine and in the diaspora of New Zealand, the US and Canada, and sheds light on the impact of the Russian- Ukrainian war on language attitudes among Ukrainians around the world. Crucially, it features an analysis of a new movement in Ukraine that developed during the course of the war – 'changing your mother tongue', which embodies what it is to renegotiate linguistic identity. It will be of value to researchers, faculty, and students in the areas of linguistics, Slavic studies, history, politics, anthropology, sociology and international affairs, as well as those interested in Ukrainian affairs more generally.
Abstract
The diffusion of knowledge is an important determinant of economic development. International trade has been established as a key mechanism in facilitating diffusion. The rise of global ...value chains (GVCs) has transformed trade in recent years. Yet the role of GVCs in giving rise to knowledge spillovers remains under-explored. In this paper, we study the elasticity of industry-level total factor productivity (TFP) to technology that is imported through intermediate trade in GVCs. To do so, we combine novel input–output decomposition methods with recent insights from the literature on the factor content of trade. We focus on a panel of 32 countries and 39 sectors over the 2000–2014 period using WIOD and OECD data. We find that domestic TFP is elastic to knowledge flows arising from GVCs and that the magnitude of this effect is larger relative to all other knowledge flows. We also find that GVC participation is particularly conducive to technology upgrading in countries that are far away from the technology frontier, and that GVC-related spillovers persist over large geographical distances.
We explore firm size heterogeneity in production networks. In comprehensive data for Belgium, firms with more customers have higher total sales but lower sales and lower market shares per customer. ...Downstream factors, especially the number of customers, explain the vast majority of firm size dispersion. We rationalize these facts with a model of network formation and two-dimensional firm heterogeneity. Higher productivity generates more matches and larger market shares among customers. Higher relationship capability generates more customers and higher sales. Model estimates suggest a strong negative correlation between productivity and relationship capability and potentially large welfare gains from improving relationship capability.
We show that family background matters significantly for children’s accumulation of wealth and investor behavior as adults, even when removing the genetic connection between children and the parents ...raising them. The analysis is made possible by linking Korean-born children who were adopted at infancy by Norwegian parents to a population panel data set with detailed information on wealth and socioeconomic characteristics. The mechanism by which these Korean-Norwegian adoptees were assigned to adoptive families is known and effectively random. This mechanism allows us to estimate the causal effects from an adoptee being raised in one type of family versus another.
We show that individuals’ macroeconomic expectations are influenced by their socioeconomic status (SES). People with higher income or higher education are more optimistic about future macroeconomic ...developments, including business conditions, the national unemployment rate, and stock market returns. The spread in beliefs between highand low-SES individuals diminishes significantly during recessions. A comparison with professional forecasters and historical data reveals that the beliefs wedge reflects excessive pessimism on the part of low-SES individuals. SES-driven expectations help explain why higher-SES individuals are more inclined to invest in the stock market and more likely to consider purchasing homes, durable goods, or cars.
Evaluating research is an established part of the research process, as funding agencies and governments seek to raise its quality and performance. The United Kingdom's Research Excellence Framework ...2021 (REF2021) was the eighth formal assessment of research in UK universities. In Business and Management Studies (B&M), Sub‐Panel 17, 108 universities submitted 16,038 research outputs and 539 impact case studies covering the period 2014–2020. Submissions were assessed by a panel of academic researchers and research users, nominated by a range of academic constituencies. The outcome was that the quality of UK research in B&M continues to improve since REF2014. The quality profile for REF2021 had 79% of research assessed as 3* (internationally excellent) and 4* (world‐leading). The paper explains and reports on our experiences of the peer review process, analyses the outcomes and discusses the state of research within the discipline. Subsequently, we consider the wider implications of the REF process, its methodologies and impacts, contributing to the debate about research quality in universities. The paper concludes with support for peer review and expresses caution against the automation of research quality assessment.
Meta-heuristic algorithms play an important role in the optimization field thanks to their robustness and programming simplicity. Many meta-heuristic methods have been devised in recent years. ...Inspired by nature, they usually simulate natural or human-specific phenomena in a better way. A large amount of them are based on complicated behaviors requiring several implementation steps and algorithm-specific control parameters, which impedes users and limits solutions to different types of optimization problems. Hence, designing effective simple and parameter-free optimization methods attracts much attention. In this paper, we propose a novel population-based optimization algorithm based on balancing composite motions (BCMO). The core idea is balancing composite motion properties of individuals in solution space. Equalizing global and local searches via a probabilistic selection model creates a movement mechanism of each individual. Four test suites selected in the literature, which vary from numerical benchmarks to practical problems, to demonstrate the performance of BCMO include: (1) 23 classical benchmark functions, (2) CEC 2005 benchmark functions, (3) CEC 2014 benchmark functions, and (4) 3 real engineering design problems. The statistical results reveal the promising performance and application of BCMO in a variety of optimization and practical problems with constrained and unknown search spaces.
Abstract
Using 9,801 director appointments during 2003–2014, we document the dramatic impact of connections. Sixty-nine percent of new directors have professional ties to incumbent boards, a group ...representing 13$\%$ of all potential candidates. Consistent with facilitating coordination and reducing search costs, connections help boards bring in gender diversity, new skills, and new industry background. More complex firms and firms in more competitive environments tend to appoint connected directors and experience better market reactions and higher shareholder votes. Connections to incumbent CEOs, however, result in lower announcement returns and shareholder votes. We use death (merger)-induced network loss (gain) as instruments.
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