Aggregate Fluctuations and International Migration

Traditional theories of integration such as the optimum currency area approach attribute a prominent role to international labour mobility in coping with relative economic fluctuations between countries. However, recent studies on international migration have overlooked the role of short-run factors in explaining international migration flows. This paper aims to fill that gap. We first derive a model of optimal migration choice based on an extension of the traditional Random Utility Model. Our model predicts that an improvement in the economic activity in a potential destination country relative to any origin country may trigger some additional migration flows on top of the impact exerted by long-run factors such as the wage differential or the bilateral distance. Compiling a dataset with annual gross migration flows between 30 developed origin and destination countries over the 1980-2010 period, we empirically test the magnitude of the effect of short-run factors on bilateral flows. Our econometric results indicate that relative aggregate fluctuations and employment rates affect the intensity of bilateral migration flows. We also provide compelling evidence that the Schengen agreements and the introduction of the euro significantly raised the international mobility of workers between the member countries

Identification of parametric models in the frequency-domain through the subspace framework under LMI constraints

International audienceIn this paper, an algorithm to identify parametric systems with an affine (or polynomial) parameter dependence through the subspace framework is proposed. It stands as an extension of the standard subspace-based algorithm which is well established in the Linear Time Invariant (LTI) case. The formulation is close to the LTI identification scheme and simply involves frequency-domain data obtained at different operating points (the parameters are frozen during each experiment). The proposed algorithm allows to identify directly a parameter-dependent model instead of interpolating multiple local models as in traditional local approaches. Another contribution is that it is possible to impose the poles location through Linear Matrix Inequalities (LMI) constraints, extending what has been done in the LTI case. This technique is applied to a numerical example and to real industrial frequency-domain data originating from an open-channel flow simulation for hydroelectricity production

Strategies for increasing contraceptive use in factories in Barbados

This report outlines results of a study on factory-based family planning operations. The 18-month study compared the relative effectiveness of two interventions: 1) ongoing contraceptive distribution by a trained factory employee supported by monthly education visits by the Barbados Family Planning Association (BFPA); and 2) monthly service and education visits by the BFPA. Service and survey data indicated that the education/information program component was stronger than the contraceptive delivery component. There were remarkable increases in the employees\u27 knowledge of contraceptive methods, especially in factories with employee distributors

Comparison of visual assessment and digital image analysis for canopy cover estimation

Nowadays, in the context of agriculture, cover crops are crops cultivated with the sole aim of providing important ecosystem services such as erosion prevention. Many services offered by these crops are directly linked to the development of their vegetation, and especially of canopy cover. A proper estimation of this cover is thus necessary to evaluate cover crop performance. Many methods to estimate canopy cover exist, but differ in terms of effort and time needed to implement them. In this study, we compared visual assessment of canopy cover in the field with two methods of digital image analysis (Assess and Canopeo), for different cover crop species and vegetation types. Visual estimation was positively correlated with both type of image analysis estimations. However, it showed systematically lower values of canopy cover, especially at intermediate canopy cover values. The type of vegetation influenced the visual and digital image estimations, narrow leaf species being the most difficult to evaluate visually. This study showed that depending on its utilisation, visual canopy cover assessment could be useful, especially when only relative estimation of canopy cover is needed. When absolute canopy cover estimation is needed, the use of digital image analysis should be preferred

Book Reviews

Book Reviews of: John H. Dryfhout, The Works of Augustus Saint-Gaudens (University Press of New England) Alan Dershowitz, The Best Defense (Random House, 1982) John LeCarré, The Little Drummer Girl (Alfred A. Knopf

A Stakeholder Informed Professional Development Framework to Support Engagement with Learning Analytics

This paper reports on a study aimed at identifying training requirements for both staff and students in higher education to enable more widespread use of learning analytics. Opinions of staff and students were captured through ten focus groups (37 students; 40 staff) and two surveys (1,390 students; 160 staff). Participants were predominantly from two higher education institutions in Ireland. Analysis of the results informed a framework for continuous professional development in learning analytics focusing on aspects of using data, legal and ethical considerations, policy, and workload. The framework presented here differentiates between the training needs of students, academic staff and professional services staff