5,607 research outputs found
Competition, Consumer Welfare, and the Social Cost of Monopoly
Conventional deadweight loss measures of the social cost of monopoly ignore, among other things, the social cost of inducing competition and thus cannot accurately capture the loss in social welfare. In this Article, we suggest an alternative method of measuring the social cost of monopoly. Using elements of general equilibrium theory, we propose a social cost metric where the benchmark is the Pareto optimal state of the economy that uses the least amount of resources, consistent with consumers' utility levels in the monopolized state. If the primary goal of antitrust policy is the enhancement of consumer welfare, then the proper benchmark is Pareto optimality, not simply competitive markets. We discuss the implications of our approach for antitrust law as well as how our methodology can be used in practice for allegations of monopoly power given a history of price-demand observations.Monopoly power, Antitrust economics, Applied general equilibrium
Earnings and Dividend Announcements is there a Corroboration Effect?
We examine abnormal stock returns surrounding contemporaneous earnings and dividend announcements in order to determine whether investors evaluate the two announcements in relation to each other.We find that there is a statistically significant interaction effect.The abnormal return corresponding to any earnings or dividend announcement depends upon the value of the other announcement. This evidence suggests the existence of a corroborative relationship between the two announcements. Investors give more credence to unanticipated dividend increases or decreases when earnings are also above or below expectations, and vice versa.
Carried or Defeated? Examining the Factors Associated with Passing School District Bond Elections in Texas, 1997-2009
Purpose: Across the United States, a large percentage of school districts are in need of facility improvements to provide safe and adequate buildings to facilitate student learning. To finance new construction, school districts traditionally have put proposals before local voters to fund construction through issuing long-term bonds to finance near-term construction. However, past literature indicates that there are few variables that are associated with bond election outcomes that are under the influence of school administrators. The purpose of this study was to examine the factors most associated with passing or failing a school district capital facility finance bond in the state of Texas from 1997 through 2009. Research Methods: We analyzed all proposed school bonds in Texas from 1997-2009, n=2,224, using a logistic regression discrete time hazard model to model the probability of passing a bond on the first, second or third attempt, while controlling for multiple types of variables such as bond, district and community characteristics, as well as specific election characteristics. Findings: We found that the first attempt of a bond is the most likely to succeed, as well as bonds that propose renovations and debt refinancing, or are at the top of the ballot. Also, while percent population over age 65 was negatively related to bond passage, percent Asian and Hispanic students was positively related. Implications for Research and Practice: Using past research and our findings, we propose a mediated model of school bond passage, and provide specific recommendations for administrators looking to pass needed facility construction bonds, including focusing on passing the bond on the first attempt and proposing only a single bond that includes all requests. Keywords: Bond issues, longitudinal studies, educational finance, facilities, school finance, school district spending, election campaigns, deb
Competition, Consumer Welfare, and the Social Cost of Monopoly
Conventional deadweight loss measures of the social cost of monopoly ignore, among other things, the social cost of inducing competition and thus cannot accurately capture the loss in social welfare. In this Article, we suggest an alternative method of measuring the social cost of monopoly. Using elements of general equilibrium theory, we propose a social cost metric where the benchmark is the Pareto optimal state of the economy that uses the least amount of resources, consistent with consumers’ utility levels in the monopolized state. If the primary goal of antitrust policy is the enhancement of consumer welfare, then the proper benchmark is Pareto optimality, not simply competitive markets. We discuss the implications of our approach for antitrust law as well as how our methodology can be used in practice for allegations of monopoly power given a history of price-demand observations
Machine Learning for Uncovering Biological Insights in Spatial Transcriptomics Data
Development and homeostasis in multicellular systems both require exquisite
control over spatial molecular pattern formation and maintenance. Advances in
spatially-resolved and high-throughput molecular imaging methods such as
multiplexed immunofluorescence and spatial transcriptomics (ST) provide
exciting new opportunities to augment our fundamental understanding of these
processes in health and disease. The large and complex datasets resulting from
these techniques, particularly ST, have led to rapid development of innovative
machine learning (ML) tools primarily based on deep learning techniques. These
ML tools are now increasingly featured in integrated experimental and
computational workflows to disentangle signals from noise in complex biological
systems. However, it can be difficult to understand and balance the different
implicit assumptions and methodologies of a rapidly expanding toolbox of
analytical tools in ST. To address this, we summarize major ST analysis goals
that ML can help address and current analysis trends. We also describe four
major data science concepts and related heuristics that can help guide
practitioners in their choices of the right tools for the right biological
questions
Switching Magnetism and Superconductivity with Spin-Polarized Current in Iron-Based Superconductor
We have explored a new mechanism for switching magnetism and
superconductivity in a magnetically frustrated iron-based superconductor using
spin-polarized scanning tunneling microscopy (SPSTM). Our SPSTM study on single
crystal SrVOFeAs shows that a spin-polarized tunneling current can
switch the Fe-layer magnetism into a non-trivial (22) order, not
achievable by thermal excitation with unpolarized current. Our tunneling
spectroscopy study shows that the induced (22) order has
characteristics of plaquette antiferromagnetic order in Fe layer and strongly
suppressed superconductivity. Also, thermal agitation beyond the bulk Fe spin
ordering temperature erases the state. These results suggest a new
possibility of switching local superconductivity by changing the symmetry of
magnetic order with spin-polarized and unpolarized tunneling currents in
iron-based superconductors.Comment: 33 pages, 16 figure
Synergistic Activation of RD29A Via Integration of Salinity Stress and Abscisic Acid in Arabidopsis thaliana.
Plants perceive information from the surroundings and elicit appropriate molecular responses. How plants dynamically respond to combinations of external inputs is yet to be revealed, despite the detailed current knowledge of intracellular signaling pathways. We measured dynamics of Response-to-Dehydration 29A (RD29A) expression induced by single or combined NaCl and ABA treatments in Arabidopsis thaliana. RD29A expression in response to a combination of NaCl and ABA leads to unique dynamic behavior that cannot be explained by the sum of responses to individual NaCl and ABA. To explore the potential mechanisms responsible for the observed synergistic response, we developed a mathematical model of the DREB2 and AREB pathways based on existing knowledge, where NaCl and ABA act as the cognate inputs, respectively, and examined various system structures with cross-input modulation, where non-cognate input affects expression of the genes involved in adjacent signaling pathways. The results from the analysis of system structures, combined with the insights from microarray expression profiles and model-guided experiments, predicted that synergistic activation of RD29A originates from enhancement of DREB2 activity by ABA. Our analysis of RD29A expression profiles demonstrates that a simple mathematical model can be used to extract information from temporal dynamics induced by combinatorial stimuli and produce experimentally testable hypotheses
Brewster-angle measurements of sea-surface reflectance using a high resolution spectroradiometer
This paper describes the design, construction and testing of a ship-borne spectroradiometer based on an imaging spectrograph and cooled CCD array with a wavelength range of 350-800 nm and 4 nm spectral sampling. The instrument had a minimum spectral acquisition time of 0.1 s, but in practice data were collected over periods of 10 s to allow averaging of wave effects. It was mounted on a ship's superstructure so that it viewed the sea surface from a height of several metres at the Brewster angle (53 degrees) through a linear polarizing filter. Comparison of sea-leaving spectra acquired with the polarizer oriented horizontally and vertically enabled estimation of the spectral composition of sky light reflected directly from the sea surface. A semi-empirical correction procedure was devised for retrieving water-leaving radiance spectra from these measurements while minimizing the influence of reflected sky light. Sea trials indicated that reflectance spectra obtained by this method were consistent with the results of radiance transfer modelling of case 2 waters with similar concentrations of chlorophyll and coloured dissolved organic matter. Surface reflectance signatures measured at three locations containing blooms of different phytoplankton species were easily discriminated and the instrument was sufficiently sensitive to detect solar-stimulated fluorescence from surface chlorophyll concentrations down to 1 mg m−3
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