Differences in Persistence Patterns Between Life and Physical Science Majors: The Role of Grades, Peers, and Preparation

Using longitudinal administrative data from a large elite research university, this paper separately analyzes the determinants of persistence for life and physical science majors. My results confirm much of the previous research on major persistence in the sciences, but I document that many findings are solely driven by persistence patterns in the physical sciences. For example, I show that the previously documented gender gap in science major persistence is due entirely to a large gap in the physical sciences. Despite large differences in persistence patterns between physical and life science, persistence in both fields is similarly influenced by grades. I provide suggestive evidence that students in both fields are “pulled away” by their high grades in non-science courses and “pushed out” by their low grades in their major field. In the physical sciences, analyses using within course and cohort variation show that peer quality in a student’s introductory courses has a lasting impact on the probability of persisting

When should precaution prevail? : interests in (public) health, the risk of harm and xenotransplantation.

Xenotransplantation is an example of a developing biotechnology which highlights three differing interests in the health of the public; a specific interest in enhancing the health of individuals who require a particular procedure or treatment, a wider interest in protecting the health of us all by avoiding introducing biotechnologies which risk the health of the public, and a public interest in advancing medical knowledge and treatment. Here we explore how matters of private benefit and public risk can be appropriately reconciled and consider whether ideas of public health should take a more central role when deciding whether clinical xenotransplantation should proceed. The risks of xenotransplantation are not certain but the nature of the harm to individual and public health could be severe. The concept of risk is central to our analysis as xenotransplantation threatens potential future harm as well as possible benefit. We argue that it is sometimes legally and ethically necessary for the state to act in advance to protect the health of the public, and that xenotransplantation is such a case. In reaching this conclusion we adopt a precautionary approach; an approach which we modify by Mill’s harm principle