Zitterbewegung is not an observable

It has recently been claimed that Zitterbewegung has been observed. However, we argue that it is not an observable and that the authors' observations must be reinterpreted

POLICY options

End of project reportThe incomes of Irish cattle farmers benefited greatly from the reform of the CAP for beef and cereals in 1992 and more recently under Agenda 2000. In both of these reforms the institutional support prices were reduced and animal-based direct payments (DPs) were used to compensate farmers for the anticipated market price reductions

What works, who works? The impact of active labour market programmes on the employment prospects of young people in Ireland

The international literature on active labour market programmes has generated inconsistent and confusing, but generally pessimistic, conclusions regarding their impact on the employment prospects of participants. This paper argues that much of this confusion is due to a general lack of attention to qualitative differences between programmes. The paper develops a typology of active labour market programmes, differentiating between training and employment measures on the basis of their orientation to the labour market and argues that programmes with a strong orientation to the market are more likely to improve the job prospects of participants than those characterised by weak market linkages. That hypothesis is tested using the results of a survey of young participants in labour market programmes in Ireland. The analysis shows that programmes with strong linkages to the labour market both enhance the employment prospects of their participants and increase their earnings, even when we take account of relevant individual characteristics such as education and previous labour market experience. -- Die internationale Literatur hat bisher inkonsistente und verwirrende, aber in der Regel pessimistische Schlußfolgerungen hinsichtlich der Beschäftigungswirkung für Teilnehmer in arbeitsmarktpolitischen Maßnahmen gezogen. In diesem Beitrag wird argumentiert, daß ein Großteil dieser Konfusion darauf zurückzuführen ist, daß den qualitativen Differenzen von Maßnahmen zu wenig Aufmerksamkeit geschenkt wurde. Es wird daher eine Typologie aktiver Arbeitsmarktpolitik entwickelt, bei der die Weiterbildungs- und Beschäftigungsmaßnahmen nach ihren Marktbezügen unterschieden werden. Maßnahmen, die sich an den Bedürfnissen des Marktes orientieren, verbessern die Beschäftigungsperspektiven der Teilnehmer deutlich mehr als Maßnahmen mit schwacher Marktorientierung. Diese These wird - unter Verwendung von Kontrollgruppen - durch eine ökonometrische Analyse von jungen Teilnehmern in Arbeitsmarktmaßnahmen in Irland getestet und bestätigt: Maßnahmen mit starker Marktorientierung erhöhen sowohl die Beschäftigungschancen als auch die Löhne der Teilnehmer, selbst wenn man die relevanten individuellen Merkmale wie Bildung und Arbeitsmarkterfahrung in Betracht zieht.

Development of a Strategic Approach for a Single EU Beef Market. Extensification. An Analysis of National and Competitive Issues

Working paperThe economic merits of the two Options for extensification under Agenda 2000 were evaluated in relation to their ability to generate revenue and their impact on the competitiveness of Irish cattle farming

The impact of feed resource costs on the relative competitiveness of beef with other meats

End of year reportThese reforms represented a major turning point in fundamental structure of EU agricultural policy. This, at the time of implementation, created much uncertainty at both institutional and farm level in relation to future feed resource costs, cattle and beef prices and related market outlooks. However, as this report shows, the reality for Irish cattle farmers was rather different. As a result much of the research effort during the lifespan of the project was diverted to explaining the causes of the unforeseen outcomes together with the implications of policy decisions and related market developments

Inevitability of Plate Tectonics on Super-Earths

The recent discovery of super-Earths (masses less or equal to 10 earth-masses) has initiated a discussion about conditions for habitable worlds. Among these is the mode of convection, which influences a planet's thermal evolution and surface conditions. On Earth, plate tectonics has been proposed as a necessary condition for life. Here we show, that super-Earths will also have plate tectonics. We demonstrate that as planetary mass increases, the shear stress available to overcome resistance to plate motion increases while the plate thickness decreases, thereby enhancing plate weakness. These effects contribute favorably to the subduction of the lithosphere, an essential component of plate tectonics. Moreover, uncertainties in achieving plate tectonics in the one earth-mass regime disappear as mass increases: super-Earths, even if dry, will exhibit plate tectonic behaviour.Comment: 13 pages, 2 figures and 1 table; in press in ApJ

Evaluating State Programmes - “Natural Experiments” and Propensity Scores

Evaluations of programmes — for example, labour market interventions such as employment schemes and training courses — usually involve comparison of the performance of a treatment group (recipients of the programme) with a control group (non-recipients) as regards some response (gaining employment, for example). But the ideal of randomisation of individuals to groups is rarely possible in the social sciences and there may be substantial differences between groups in the distributions of individual characteristics that can affect response. Past practice in economics has been to try to use multiple regression models to adjust away the differences in observed characteristics, while also testing for sample selection bias. The Propensity Score approach, which is widely applied in epidemiology and related fields, focuses on the idea that “matching” individuals in the groups should be compared. The appropriate matching measure is usually taken to be the prior probability of programme participation. This paper describes the key ideas of the Propensity Score method and illustrates its application by reanalysis of some Irish data on training courses.