The Effects of Legalized Abortion in England

Dr. O\u27Sullivan traces the process leading to the passage of the 1968 British Abortion Act and the consequences of that act with a view to helping the American medical profession learn from the British experience. This article discusses the effect that legalized abortion has had upon the people, and particularly the physicians, in England. Although New York State, among others, has now legalized abortion, it has not had sufficient experience with it to adequately assess its effects. But the English have had sufficient experience with it, and its effects there indicate that attempts to legalize abortion demand close watching. Reprinted with permission from Hospital Progress June, 1970

Refinancing Europe’s Higher Education through Deferred and Income-Contingent Fees: An empirical assessment using Belgian, German and UK data

The arguments for refinancing the European Union's (EU) higher education via higher tuition fees largely rest on preserving the profitability of the educational investment and offering deferred and income-contingent payments. Using income survey datasets on Belgium, Germany and the United Kingdom (UK) we first estimate how graduates' private return on educational investment is likely to be affected by higher private contributions. We then evaluate the effect of income-contingent and deferred payment mechanisms on lifetime net income and its capacity to account for graduates' ability to pay, considering numerous ways of financing the cost of introducing income-contingency. Our analysis reveals that increasing individuals' contributions to higher education costs, through income-contingent and deferred instruments, does not significantly affect the private rate of return of heterogeneous graduates, allows for payments to be indexed to ability to pay, and can be implemented in ways that minimize the risk of adverse selection. These findings prove robust to significant variations between countries' unharmonised higher education institutional structures.Higher Education Finance, income-contingent loans, risk pooling and risk shifting

Environmental sustainability conducts and corporate performance in extractive sector

The subject of environmental sustainability transcends geographical zones, it attracts attention at the top-most business, governmental and civil society levels because of its current visible impacts. Despite the growing concern for a sustainable ecosystem, few applied studies have been conducted to establish the relationship between environmental sustainability and corporate performance in the extractive sector (one of the most profitable of all business sectors, yet arguably the worst culprit in environmental degradation). Therefore, this research seeks to explore the relationship between environmental sustainability and corporate performance in the extractive sector. This relationship was investigated using data from 68 companies within the extractive sector in both Europe and the Americas by the technique of multiple linear regression and event studies by one-way ANOVA. Our results show a negative relationship between environmental sustainability and profit while mixed results were obtained for relationship between environmental sustainability and firm value. In the short horizon, there is a positive relationship between environmental sustainability and firm value while a negative result was obtained in a long-horizon. The pattern of the results is most likely due to the unique nature of the sector where the demand for product exceeds supply. There is monopoly power in the form of cartels, and substitutes for the sector’s products (e.g. oil, gas, and cement) are either unavailable or inadequate. Therefore, poor attention to environmental responsibilities may not necessarily affect the profit but impact negatively on corporate value of the companies within the sector in a short-term. However, in the long-term, poor sensitivity to the environment may not be sustainable

Multisource Bayesian sequential change detection

Suppose that local characteristics of several independent compound Poisson and Wiener processes change suddenly and simultaneously at some unobservable disorder time. The problem is to detect the disorder time as quickly as possible after it happens and minimize the rate of false alarms at the same time. These problems arise, for example, from managing product quality in manufacturing systems and preventing the spread of infectious diseases. The promptness and accuracy of detection rules improve greatly if multiple independent information sources are available. Earlier work on sequential change detection in continuous time does not provide optimal rules for situations in which several marked count data and continuously changing signals are simultaneously observable. In this paper, optimal Bayesian sequential detection rules are developed for such problems when the marked count data is in the form of independent compound Poisson processes, and the continuously changing signals form a multi-dimensional Wiener process. An auxiliary optimal stopping problem for a jump-diffusion process is solved by transforming it first into a sequence of optimal stopping problems for a pure diffusion by means of a jump operator. This method is new and can be very useful in other applications as well, because it allows the use of the powerful optimal stopping theory for diffusions.Comment: Published in at http://dx.doi.org/10.1214/07-AAP463 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

Prioritizing Populations for Conservation Using Phylogenetic Networks

In the face of inevitable future losses to biodiversity, ranking species by conservation priority seems more than prudent. Setting conservation priorities within species (i.e., at the population level) may be critical as species ranges become fragmented and connectivity declines. However, existing approaches to prioritization (e.g., scoring organisms by their expected genetic contribution) are based on phylogenetic trees, which may be poor representations of differentiation below the species level. In this paper we extend evolutionary isolation indices used in conservation planning from phylogenetic trees to phylogenetic networks. Such networks better represent population differentiation, and our extension allows populations to be ranked in order of their expected contribution to the set. We illustrate the approach using data from two imperiled species: the spotted owl Strix occidentalis in North America and the mountain pygmy-possum Burramys parvus in Australia. Using previously published mitochondrial and microsatellite data, we construct phylogenetic networks and score each population by its relative genetic distinctiveness. In both cases, our phylogenetic networks capture the geographic structure of each species: geographically peripheral populations harbor less-redundant genetic information, increasing their conservation rankings. We note that our approach can be used with all conservation-relevant distances (e.g., those based on whole-genome, ecological, or adaptive variation) and suggest it be added to the assortment of tools available to wildlife managers for allocating effort among threatened populations

Imaging a boson star at the Galactic center

Millimeter very long baseline interferometry will soon produce accurate images of the closest surroundings of the supermassive compact object at the center of the Galaxy, Sgr A*. These images may reveal the existence of a central faint region, the so-called shadow, which is often interpreted as the observable consequence of the event horizon of a black hole. In this paper, we compute images of an accretion torus around Sgr A* assuming this compact object is a boson star, i.e. an alternative to black holes within general relativity, with no event horizon and no hard surface. We show that very relativistic rotating boson stars produce images extremely similar to Kerr black holes, showing in particular shadow-like and photon-ring-like structures. This result highlights the extreme difficulty of unambiguously telling the existence of an event horizon from strong-field images.Comment: 21 pages, 9 figures, accepted in CQG; main difference wrt previous version is the last paragraph of the conclusio