Structural estimates of equilibrium unemployment in six OECD economies

In Europe, neither unemployment rates nor institutions are uniform. In the EMU, countries have coordinated their monetary policy, and fiscal policy might follow. Does convergence in fiscal policy imply that unemployment rates will converge, too, or is diversified fiscal policy desirable? An answer to this question requires insight into the dependence on fiscal policy of the unemployment rate in equilibrium. This study estimates the equilibrium rate of unemployment and shows that it has been affected significantly by taxes and benefits. Uniform fiscal policy would not, however, harmonise the unemployment rates because the impact of policy varies widely across the OECD economies.

Task allocation in dynamic networks of satellites

The management of distributed satellite systems requires the coordination of a large number of heterogeneous spacecraft. Task allocation in such a system is complicated by limited communication and individual satellite dynamics. Previous work has shown that task allocation using a market-based mechanism can provide scalable and efficient management of static networks; in this paper we extend this work to determine the impact of dynamic topologies. We develop a Keplerian mobility model to describe the topology of the communication network over time. This movement model is then used in simulation to show that the task allocation mechanism does not show a significant decrease in effectiveness from the static case, reflecting the suitability distributed market-based control to the highly dynamic environment

SGR J1550–5418 Bursts Detected with the Fermi Gamma-Ray Burst Monitor during its Most Prolific Activity

We have performed detailed temporal and time-integrated spectral analysis of 286 bursts from SGR J1550–5418 detected with the Fermi Gamma-ray Burst Monitor (GBM) in 2009 January, resulting in the largest uniform sample of temporal and spectral properties of SGR J1550–5418 bursts. We have used the combination of broadband and high time-resolution data provided with GBM to perform statistical studies for the source properties. We determine the durations, emission times, duty cycles, and rise times for all bursts, and find that they are typical of SGR bursts. We explore various models in our spectral analysis, and conclude that the spectra of SGR J1550–5418 bursts in the 8-200 keV band are equally well described by optically thin thermal bremsstrahlung (OTTB), a power law (PL) with an exponential cutoff (Comptonized model), and two blackbody (BB) functions (BB+BB). In the spectral fits with the Comptonized model, we find a mean PL index of –0.92, close to the OTTB index of –1. We show that there is an anti-correlation between the Comptonized E_(peak) and the burst fluence and average flux. For the BB+BB fits, we find that the fluences and emission areas of the two BB functions are correlated. The low-temperature BB has an emission area comparable to the neutron star surface area, independent of the temperature, while the high-temperature BB has a much smaller area and shows an anti-correlation between emission area and temperature. We compare the properties of these bursts with bursts observed from other SGR sources during extreme activations, and discuss the implications of our results in the context of magnetar burst models

New Economic Geography, Empirics, and Regional Policy

There are doubts about the effectiveness of regional policy. Well known are the vain attempts of Italy to bridge the gap between the Mezzogiorno and the North, of Germany to bridge the gap between the Neue Länder and the West, and of the European Commission to reduce regional disparities in general. We validate a salient explanation for the lack of effectiveness: agglomeration advantages lock business activity in relatively prosperous core regions, even though wages and production costs tend to be higher there. On the basis of the `New Economic Geography' - a set of general equilibrium models that focus on location choice - in combination with descriptive statistics and econometric analysis, we conclude that the European economic geography is characterized by a network of local and stable core-periphery systems. Since regional policy tend to be insufficient to counter centripetal market forces, disparities between cores and their peripheries at a subprovincial level of regional aggregation are with us to stay. Moreover, if regional policy does have an impact, it may be adverse as some policies targeted on peripheral regions trigger location choices in favour of core regions.

Distributed and Centralized Task Allocation: When and Where to Use Them

Self-organisation is frequently advocated as the solution for managing large, dynamic systems. Distributed algorithms are implicitly designed for infinitely large problems, while small systems are regarded as being controllable using traditional, centralised approaches. Many real-world systems, however, do not fit conveniently into these "small" or "large" categories, resulting in a range of cases where the optimal solution is ambiguous. This difficulty is exacerbated by enthusiasts of either approach constructing problems that suit their preferred control architecture. We address this ambiguity by building an abstract model of task allocation in a community of specialised agents. We are inspired by the problem of work distribution in distributed satellite systems, but the model is also relevant to the resource allocation problems in distributed robotics, autonomic computing and wireless sensor networks. We compare the behaviour of a self-organising, market-based task allocation strategy to a classical approach that uses a central controller with global knowledge. The objective is not to prove one mechanism inherently superior to the other; instead we are interested in the regions of problem space where each of them dominates. Simulation is used to explore the trade-off between energy consumption and robustness in a system of intermediate size, with fixed communication costs and varying rates of component failure. We identify boundaries between regions in the parameter space where one or the other architecture will be favoured. This allows us to derive guidelines for system designers, thus contributing to the development of a disciplined approach to controlling distributed systems using self-organising mechanisms

Documentation of CORTAX

CORTAX is applied in Bettendorf et al. (2006), a simulation study on the economic and welfare implications of reforms in corporate income taxation. This technical documentation of the model consists of the derivation and listing of the equations of the model and a justification of the calibration.

BUDGET PERSPECTIVES 2008. IS EU COORDINATION NEEDED FOR CORPORATE TAXATION?

Should EU-member states give up their rights to design their own corporate income tax? Currently, member states are free to set their tax rates and are allowed to design their tax base as long as it does not constitute harmful tax competition. This is regulated in the Code of Conduct, which is not a legally binding instrument but does have political force. By adopting this Code, the member states have undertaken to roll back existing tax measures that constitute harmful tax competition and refrain from introducing any such measures in the future