Job Mobility and Wage Dynamics

Matched employer-employee data research has found that workersf wages are affected by the characteristics of the firms they work in, and that higher skilled workers tend to be employed by higher paying firms. This paper examines the contribution of workersf job mobility to their wage dynamics. We focus on the possible trade-off between moving to a better paying firm and losing a firm-tenure specific component of earnings, and examine what types of workers benefit from changing firms, rather than staying with their existing employer. Our analysis provides four main findings. First, although the raw earnings gains to jobmovers and stayers are about the same, we find that, after controlling for observable differences, job-movers have about 1.3 percent lower annual earnings growth than nonmovers. Second, we estimate that job-movers gain 0.3 percent per year on average from moving to higher paying firms, but lose 1.6 percent in transitory earnings associated with changing jobs. The gains from moving to better firms are larger for both younger and new entrant workers, while the transitory earnings losses are smaller. We interpret these findings as being due to an earnings growth trade-off for workers between moving to a higher paying firm and losing their tenure-related earnings at their existing firm. Third, we estimate that, on average, workers gain (almost) all of the change in firm earnings premiums when they change jobs. However, such gains are not equally shared by all workers. In particular, our estimates suggest that it is the higher ability workers (as measured by the estimated worker earnings premiums) whose earnings gain (or lose) the most from moving to a firm with higher (or lower) earnings premiums. Finally, we find that workersf earnings also benefit on average from a change in the average earnings of their co-workers. Controlling for other factors, we estimate that a 1 standard deviation change in the estimated average peer earnings is associated with about 0.25 percent change in a workerfs earnings on average.Earnings, Linked Employer-Employee Data, worker mobility, job turnover

Effects of Nonmaternal Child Care on Inequality in Cognitive Skills

As a result of changing welfare policies, large numbers of children of poor, uneducated mothersare likely to receive care from others as their mothers enter the workforce. How will this change affect inequality in cognitive skills among young children? One view suggests that inequality will expand because children from economically advantaged families have access to better child care, and families with well-educated parents are more likely to reinforce the cognitive benefits of care. Another view argues that inequality will diminish because even though child care may be unequal, it may be less unequal than the home environments that are supplanted by nonmaternal care. A third view suggests that because the effects of care are inconsistent, there will be little overall change in inequality. Analysis of the children of mothers in the National Longitudinal Survey of Youth provides tentative evidence in support of the first view, that nonmaternal care tends to magnify inequality. Although ordinary least squares regressions reveal no effects of child care, fixed-effects models that control for differences between families indicate that children of high-income, well-educated mothers benefit from center-based care, but children of low-income, poorly educated mothers suffer a cognitive disadvantage from attending day care centers. Home-based care, however, is not associated with cognitive performance. Results from nonparametric analyses are consistent with the findings from fixed-effects models. The key results rely mainly on a relatively small sample of about 700 children in 300 families that sent their children to different types of care, and they do not pertain to families with only one child, so caution is warranted in generalizing the findings.

Earnings Heterogeneity and Job Matching - Evidence from Linked Employer-Employee Data

This paper uses data from Statistics New Zealand’s linked Employer-Employee Database (LEED) over the six-year period April 1999 – March 2005 to derive and analyse estimates of two-way worker and from fixed efforts components of job earnings rates. The fixed effects estimates reflect the portable earnings premium that each worker receives in whichever firm they work for, and the time-invariant premium that each firm pays to all the workers in employs. We focus on three issues. First, how much of the variation in job earnings rates is attributable to observable worker demographic factors (age and gender), unobserved worker effects and unobserved firm effects? Second, how much compositional change occurred during this period of substantial employment growth? Third, what is the aggregate pattern of sorting of workers and firms across jobs

Opinion formation models based on game theory

A way to simulate the basic interactions between two individuals with different opinions, in the context of strategic game theory, is proposed. Various games are considered, which produce different kinds of opinion formation dynamics. First, by assuming that all individuals (players) are equals, we obtain the bounded confidence model of continuous opinion dynamics proposed by Deffuant et al. In such a model a tolerance threshold is defined, such that individuals with difference in opinion larger than the threshold can not interact. Then, we consider that the individuals have different inclinations to change opinion and different abilities in convincing the others. In this way, we obtain the so-called ``Stubborn individuals and Orators'' (SO) model, a generalization of the Deffuant et al. model, in which the threshold tolerance is different for every couple of individuals. We explore, by numerical simulations, the dynamics of the SO model, and we propose further generalizations that can be implemented.Comment: 18 pages, 4 figure

The effect of organic management on soil quality indicators

This report was presented at the UK Organic Research 2002 Conference. A range of physical, biological and chemical parameters were measured in organic soil that had been managed in different ways and in a conventional control. Factors were identified that could be used to construct an index of soil quality

A Branch-and-Price Approach for a Ship Routing Problem with Multiple Products and Inventory Constraints

In the oil industry, different oil components are blended in a refinery to fuel products. These products are transported to different harbors by ship. Due to the limited storage capacity at the harbors and the undesirability of a stock-out, inventory levels at the harbors have to be taken into account during the construction of the ship routes. In this paper, we give a detailed description of this problem, which we call the ship routing problem with multiple products and inventory constraints. Furthermore, we formulate this problem as a generalized set-covering problem, and we present a Branch-and-Price algorithm to solve it. The pricing problems have a very complex nature. We discuss a dynamic programming algorithm to solve them to optimality

Economic evaluations using genetic algorithms to determine the territorial impact caused by high speed railways

The evolution of technology and construction techniques has enabled the upgrading of transport networks. In particular, the high-speed rail networks allow convoys to peak at above 300 km/h. These structures, however, often significantly impact the surrounding environment. Among the effects of greater importance are the ones provoked by the soundwave connected to train transit. The wave propagation affects the quality of life in areas surrounding the tracks, often for several hundred metres. There are substantial damages to properties (buildings and land), in terms of market depreciation. The present study, integrating expertise in acoustics, computering and evaluation fields, outlines a useful model to select project paths so as to minimize the noise impact and reduce the causes of possible litigation. It also facilitates the rational selection of initiatives to contain the environmental damage to the already existing railway tracks. The research is developed with reference to the Italian regulatory framework (usually more stringent than European and international standards) and refers to a case study concerning the high speed network in Italy

From Goya to Afghanistan. An essay on the ratio and ethics of medical war pictures

For centuries pictures of the dead and wounded have been part and parcel of war communications. Often the intentions were clear, ranging from medical instructions to anti-war protests. The public's response could coincide with or diverge from the publisher's intention. Following the invention of photography in the nineteenth century, and the subsequent claim of realism, the veracity of medical war images became more complex. Analysing and understanding such photographs have become an ethical obligation with democratic implications. We performed a multidisciplinary analysis of War Surgery (2008), a book containing harsh, full-colour photographs of mutilated soldiers from the Iraq and Afghanistan wars. Our analysis shows that, within the medical context, this book is a major step forward in medical war communication and documentation. In the military context the book can be conceived as an attempt to put matters right given the enormous sacrifice some individuals have suffered. For the public, the relationship between the 'reality' and 'truth' of such photographs is ambiguous, because only looking at the photographs without reading the medical context is limiting. If the observer is not familiar with medical practice, it is difficult for him to fully assess, signify and acknowledge the value and relevance of this book. We therefore assert the importance of the role of professionals and those in the humanities in particular in educating the public and initiating debate. © 2010 Taylor & Francis