A theoretical analysis of random inspections and fines in invasive species management

In this paper, we conduct a theoretical analysis of inspections in a stochastic environment and we shed light on two hitherto unstudied issues concerning inspections in the context of invasive species management. First, given a particular port of entry in a country, we study the properties of a random inspection scheme. Second, we compute the average total fines that will be collected in the long run by an inspection agency that uses the above inspection scheme to screen arriving ships for the presence of one or more invasive species.Invasive Species

INDIVISIBILITY AND DIVISIBILITY IN LAND DEVELOPMENT DECISIONS OVER TIME AND UNDER UNCERTAINTY

The quasi-option value (QOV) literature originated by Arrow and Fisher (1974) and by Henry (1974) is largely concerned with the analysis of two-period models of land development. Our paper extends this literature by analyzing two scenarios in which the decision to develop land is made in a multi-period and stochastic framework. In the first scenario, the development decision is indivisible. In contrast, in the second scenario, the development decision is divisible. Specifically, we study the properties of the indivisible development decision when there is a time constraint on when land is to be developed. We then analyze the ways in which the divisible land development decision depends on the extent of a landowner's landholding and on the number of development opportunities awaiting this landowner.Land Economics/Use,

Surface self-diffusion of vanadium

The decay of periodic profile on the surfaces of single crystalline vanadium specimen is orientation dependent. Faceting occurs on both (100) and (110) surfaces. Periodic profile becomes sinusoidal on the (111) surface and the sinusoidal profile becomes distorted on a surface 9(DEGREES) away from the (111) plane. The surface self-diffusion coefficient of vanadium was determined by using Mullins\u27 theory of sinusoidal profile decay on the (111) surface. The results are;(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI);and;(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI);The anisotropy indicates that the effect of ledges cannot be neglected. The experimental activation energy is lower than that calculated from the pairwise interaction model and the heat of sublimation. This difference is attributed to the fact that the model does not account for both the lattice relaxation and the electron redistribution at the surface. In general, the surface self-diffusion coefficients of bcc refractory metals can be expressed as;(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI);This expression predicts the diffusion coefficients to within a factor of two or three

The Search for Meaning: Survivors’ Children and Their Choice of a Life in the Law

Rose Zoltek-Jick is an associate teaching professor and the associate director of the Civil Rights and Restorative Justice Project at Northeastern University School of Law, Boston. She delivered the following talk in Boston on January 23, 2017, during Northeastern’s annual Holocaust Awareness Week

Metformin, Sulfonylureas, or Other Antidiabetes Drugs and the Risk of Lactic Acidosis or Hypoglycemia

OBJECTIVE: Lactic acidosis has been associated with use of metformin. Hypoglycemia is a major concern using sulfonylureas. The aim of this study was to compare the risk of lactic acidosis and hypoglycemia among patients with type 2 diabetes using oral antidiabetes drugs. RESEARCH DESIGN AND METHODS: This study is a nested case-control analysis using the U.K.-based General Practice Research Database to identify patients with type 2 diabetes who used oral antidiabetes drugs. Within the study population, all incident cases of lactic acidosis and hypoglycemia were identified, and hypoglycemia case subjects were matched to up to four control patients based on age, sex, practice, and calendar time. RESULTS: Among the study population of 50,048 type 2 diabetic subjects, six cases of lactic acidosis during current use of oral antidiabetes drugs were identified, yielding a crude incidence rate of 3.3 cases per 100,000 person-years among metformin users and 4.8 cases per 100,000 person-years among users of sulfonylureas. Relevant comorbidities known as risk factors for lactic acidosis could be identified in all case subjects. A total of 2,025 case subjects with hypoglycemia and 7,278 matched control subjects were identified. Use of sulfonylureas was associated with a materially elevated risk of hypoglycemia. The adjusted odds ratio for current use of sulfonylureas was 2.79 (95% CI 2.23–3.50) compared with current metformin use. CONCLUSIONS: Lactic acidosis during current use of oral antidiabetes drugs was very rare and was associated with concurrent comorbidity. Hypoglycemic episodes were substantially more common among sulfonylurea users than among users of metformin.Merck SA, Lyon, Franc

Use of depot medroxyprogesterone acetate and fracture risk

Depot medroxyprogesterone acetate (DMPA), which has a high rate of use among teenagers in Europe and the United States, has been associated with impaired bone mineral acquisition during adolescence and accelerated bone loss in later life. Studies on the association between DMPA use and fracture risk are limited.; We aimed at evaluating the relationship between use of hormonal contraceptives, specifically DMPA, and fracture risk.; We conducted a case-control analysis using the United Kingdom-based General Practice Research Database.; Participants were females aged 20-44 yr with an incident fracture diagnosis between 1995 and 2008.; Odds ratios (OR) with 95% confidence intervals (CI) of incident fracture in relation to exposure to DMPA or combined oral contraceptives were assessed. Adjustments were made for smoking, body mass index, and additional potential confounders.; We identified 17,527 incident fracture cases and 70,130 control patients (DMPA exposure: 11 and 8%, respectively). Compared with nonuse, current use of one to two, three to nine, or 10 or more DMPA prescriptions yielded adjusted OR for fractures of 1.18 (95% CI = 0.93-1.49), 1.36 (95% CI = 1.15-1.60), and 1.54 (95% CI = 1.33-1.78), respectively. Fracture risk was highest after longer treatment duration (<2-3 yr), and there was no difference in patients below and above the age of 30 yr. For users of combined estrogen-containing oral contraceptives, the OR were around 1.; This population-based study suggests that use of DMPA is associated with a slightly increased risk of fractures

A Theoretical Analysis of Preference Matching by Tourists and Destination Choice

How does the phenomenon of preference matching by tourists affect their choice between two possible destinations? We study this question. It costs less (more) to vacation in destination A (B). Tourists choose to either vacation in A or B. They differ in their incomes. These incomes are uniformly distributed on the unit interval. Our analysis leads to four results. First, when the cost differential parameter satisfies a particular condition, both destinations are visited in the equilibrium. Second, when this parametric condition holds, in any equilibrium in which the mean income of the tourists varies across the two destinations, every tourist vacationing in A has a lower income than every tourist vacationing in B. Third, there exists an income cutoff point and all tourists with lower (higher) incomes choose to vacation in A (B). Finally, in the equilibrium with income sorting, it is possible to make all tourists better off by modifying their destination choices

Using a Local Public Good to Attract Representative Creative Class Members: The Inefficient Equilibrium Case

Batabyal and Beladi (2019) have recently analyzed a model of competition between two cities that use a local public good (LPG) to attract members of the creative class. The creative class consists of artists and engineers and they study the behavior of a representative artist and an engineer. In this note, we explore three implications of the use of this “representative artist and engineer” modeling strategy. First, we show that the use of such a strategy can lead one to study an inefficient equilibrium in the aggregate economy. Second, we point out that in this inefficient equilibrium, the beliefs of the representative artist and the engineer are inconsistent. Finally, we contend that if we depart from the “representative artist and engineer” construct and focus instead on the entire creative class population which we model as a continuum, then the inefficient equilibrium mentioned above can be turned into an efficient equilibrium

Using a Local Public Good to Attract Representative Creative Class Members: The Inefficient Equilibrium Case

Batabyal and Beladi (2019) have recently analyzed a model of competition between two cities that use a local public good (LPG) to attract members of the creative class. The creative class consists of artists and engineers and they study the behavior of a representative artist and an engineer. In this note, we explore three implications of the use of this “representative artist and engineer” modeling strategy. First, we show that the use of such a strategy can lead one to study an inefficient equilibrium in the aggregate economy. Second, we point out that in this inefficient equilibrium, the beliefs of the representative artist and the engineer are inconsistent. Finally, we contend that if we depart from the “representative artist and engineer” construct and focus instead on the entire creative class population which we model as a continuum, then the inefficient equilibrium mentioned above can be turned into an efficient equilibrium