Boston College

About: Boston College is a education organization based out in Boston, Massachusetts, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 9749 authors who have published 25406 publications receiving 1105145 citations. The organization is also known as: BC.

Do Buyouts (Still) Create Value

Abstract: We examine whether, and how, leveraged buyouts from the most recent wave of public to private transactions created value. For a sample of 192 buyouts completed between 1990 and 2006, we show that these deals are somewhat more conservatively priced and less levered than their predecessors from the 1980s. For the subsample of deals with post-buyout data available, median market and risk adjusted returns to pre- (post-) buyout capital invested are 72.5% (40.9%). In contrast, gains in operating performance are either comparable to or slightly exceed those observed for benchmark firms. Increases in industry valuation multiples and realized tax benefits from increasing leverage while private are each economically as important as operating gains in explaining realized returns.

Negative flat band magnetism in a spin–orbit-coupled correlated kagome magnet

Abstract: Electronic systems with flat bands are predicted to be a fertile ground for hosting emergent phenomena including unconventional magnetism and superconductivity1–15, but materials that manifest this feature are rare. Here, we use scanning tunnelling microscopy to elucidate the atomically resolved electronic states and their magnetic response in the kagome magnet Co3Sn2S2 (refs. 16–20). We observe a pronounced peak at the Fermi level, which we identify as arising from the kinetically frustrated kagome flat band. On increasing the magnetic field up to ±8 T, this state exhibits an anomalous magnetization-polarized many-body Zeeman shift, dominated by an orbital moment that is opposite to the field direction. Such negative magnetism is induced by spin–orbit-coupling quantum phase effects21–25 tied to non-trivial flat band systems. We image the flat band peak, resolve the associated negative magnetism and provide its connection to the Berry curvature field, showing that Co3Sn2S2 is a rare example of a kagome magnet where the low-energy physics can be dominated by the spin–orbit-coupled flat band. The authors show that a magnetic material with kagome lattice planes hosts a flat band near the Fermi level. Electrons in this band exhibit ‘negative magnetism’ due to the Berry curvature.

The Changing Incidence of Geography

Abstract: The incidence of bilateral trade costs is calculated here using neglected properties of the structural gravity model, disaggregated by commodity and region, and re- aggregated into forms useful for economic geography. For Canada's provinces, 1992-2003, sellers' incidence is on average some five times higher than buyers' incidence. Sellers' incidence falls over time due to specialization, despite constant gravity coefficients. This previously unrecognized globalizing force drives big reductions in "constructed home bias," the disproportionate predicted share of local trade; and large but varying gains in real GDP. (7£LF11,F14,R12) The large gravity literature has revealed much information about bilateral trade costs (Anderson and Eric van Wincoop 2004). But the literature has not addressed incidence: the proportions of trade costs paid by sellers and buyers. The omission is important because incidence is what matters for most issues of regional specialization, welfare and policy. For example, even with uniform trade costs, sectors with larger sellers' incidence will tend to have smaller supply, all else equal. As for welfare and policy, uniform trade cost reductions confer benefits with buyers' and sellers' incidence varying across trade partners. Recently discovered properties of structural gravity are used here to calculate sectoral incidence measures of trade costs for Canada's provinces, 1992-2003. We uncover a secular fall in sellers' incidence that induces a fall in home bias and a rise in real GDP. This reflects a previously unrecognized force of globalization: specialization acting to reduce the trade cost bill. We add to the gravity literature new methods and new empirical lessons about Canada's trade costs.1 Inward and outward multilateral resistance (Anderson and van Wincoop 2003, 2004)

The Five Cs Model of Positive Youth Development: A Longitudinal Analysis of Confirmatory Factor Structure and Measurement Invariance

Abstract: The understanding of positive development across adolescence rests on having a valid and equivalent measure of this construct across the breadth of this period of life. Does the Positive Youth Development (PYD) construct based on the Five Cs model have satisfactory psychometric properties for such longitudinal measurement invariance? Using longitudinal data derived from the 4-H Study of PYD, we assessed 920 youth (61.6% female) from a racially and ethically diverse sample (67.3% European American) who participated in three waves (Grades 8-10) of data collection. Building on prior findings that the Five Cs (i.e., Competence, Confidence, Connection, Character, and Caring) model of PYD was a robust measure that could be assessed comparably during early adolescence, we tested a hierarchy of second-order confirmatory factor analysis models to assess the extent to which PYD can be measured equivalently across middle adolescence. Evidence was found for strict measurement invariance across three measurement occasions, including equivalence of first-order and second-order factor loadings, equality of intercepts of observed variables, and equality of item uniqueness and disturbances of the first-order factors. These results suggest that PYD can be measured in the same way across measurement occasions, a prerequisite for the study of development. Implications for research and application of being able to measure PYD equivalently across adolescence are discussed.

Reliability of reports of violent victimization and posttraumatic stress disorder among men and women with serious mental illness

Abstract: Although violent victimization is highly prevalent among men and women with serious mental illness (SMI; e.g., schizophrenia, bipolar disorder), future research in this area may be impeded by controversy concerning the ability of individuals with SMI to report traumatic events reliably. This article presents the results of a study exploring the temporal consistency of reports of childhood sexual abuse, adult sexual abuse, and adult physical abuse, as well as current symptoms of posttraumatic stress disorder (PTSD) among 50 people with SMI. Results show that trauma history and PTSD assessments can, for the most part, yield reliable information essential to further research in this area. The study also demonstrates the importance of using a variety of statistical methods to assess the reliability of self-reports of trauma history.