Optimal Simple Rules for Fiscal Policy in a Monetary Union

The paper discusses the stabilizing potential of fiscal policy in a dynamic general-equilibrium model of monetary union. We consider a small open economy inside the currency area. We analyze the demand and supply effects of direct taxation, indirect taxation and government spending and derive optimal simple rules for fiscal stabilization of a technology shock. Fiscal policy achieves substantial macroeconomic stabilization. Simple public-expenditure rules show the highest degree of both output and inflation stabilization. The implementation lag substantially weakens output stabilization, but hardly affects the stabilization of prices. Out-put-oriented rules imply less instrument inertia than inflation-dominated rules. The implemen-tation lag leads to higher coefficients for inflation relative to output in the optimal rule. Com-pared to the single-instrument approach the simultaneous optimization of two instrument rules implies only little additional stabilization gains.Fiscal policy, monetary union, simple policy rules

Competing Motivations in Germany’s Higher Education Response to the “Refugee Crisis”

In 2015–16 Germany was confronted with over 1 million new refugees, which challenged public and private institutions alike and increasingly divided public sentiments. This article investigates the cultural, political, and economic dynamics as they were in Germany in 2015–16 and in particular how its higher education sector responded. The discussion covers a comprehensive review of media debates, public and private institutional research, new German- and English-language scholarship, and case studies the authors collected of fiffeen universities. The article ends with recommendations as German universities prepare for 30,000–50,000 refugees eligible for study in the coming years. En 2015-2016, l’Allemagne a fait face à plus de 1 million de nouveaux réfugiés, ce qui a remis en question les institutions publiques et privées et généré des sentiments de plus en plus divisés de la part du public. Cet article explore les dynamiques économiques, politiques et culturelles telles qu’elles se présentaient en Allemagne ces années-là, et en particulier la réaction de son enseignement supérieur. La discussion porte sur un examen exhaustif des débats médiatiques, de la recherche institutionnelle publique et privée, des nouvelles bourses d’études pour apprendre l’allemand ou l’anglais, et d’études de cas colligées par les auteurs dans 15 universités. L’article se termine sur des recommandations, alors que les universités allemandes se préparent à accueillir de 30 000 à 50 000 réfugiés admissibles aux études dans les années à venir.&nbsp

An Architecture for Self-Aware IOT Applications

Future Internet of Things (IoT) applications will face challenges in increased flexibility, uncertainty, dynamics and scalability. Self-aware computing maintains knowledge about the applications state and environment and then uses this knowledge to reason about and adapt behaviours. In this position paper, we introduce self-aware computing as design approach for IoT applications which is centred around a self-aware architecture for IoT nodes. This architecture particularly supports adaptations based on node interactions. We demonstrate our approach with an IoT case study on multi-object coverage with mobile cameras

Labour hoarding during the pandemic: assessing the impact of job retention schemes in Europe

Job retention schemes have helped Europe to avoid mass unemployment during the Covid-19 pandemic. Bernhard Ebbinghaus and Lukas Lehner write that while these schemes had an immediate impact during lockdown, the future development and long-term consequences of job retention policies remain uncertain

Optimal Simple Rules for Fiscal Policy in a Monetary Union

The paper discusses the stabilizing potential of fiscal policy in a dynamic general-equilibrium model of monetary union. We consider a small open economy inside the currency area. We analyze the demand and supply effects of direct taxation, indirect taxation and government spending and derive optimal simple rules for fiscal stabilization of a technology shock. Fiscal policy achieves substantial macroeconomic stabilization. Simple public-expenditure rules show the highest degree of both output and inflation stabilization. The implementation lag substantially weakens output stabilization, but hardly affects the stabilization of prices. Out-put-oriented rules imply less instrument inertia than inflation-dominated rules. The implemen-tation lag leads to higher coefficients for inflation relative to output in the optimal rule. Com-pared to the single-instrument approach the simultaneous optimization of two instrument rules implies only little additional stabilization gains

Structural reforms and the exchange rate regime: a panel analysis for the world versus OECD countries

We test the significance of the relationship between the exchange rate regime and the degree of structural reforms by estimating panel regressions for a world and an OECD country sample. The empirical results suggest a positive correlation between on the one side the adoption of an exchange rate rule and on the other side overall structural reforms as well as reforms in the money and banking sector in the broad country sample. For government size and for market regulation, we do not find any robust significant effect, however. The results do not confirm the main implication of Calmfors-type models, namely a higher degree of reforms under monetary policy autonomy. They corroborate conditional policy convergence and, partly, that limiting monetary policy autonomy fosters structural reforms

Simulating the opening of a champagne bottle

The axially symmetric, swirl-free gas dynamics and interlinked motion of a cork stopper provoked by the opening of a champagne bottle are modelled rigorously and studied numerically. The experimental study by Liger-Belair, Cordier \& Georges (Science Advances, 5(9), 2019) animated the present investigation. Inspection analysis justifies the inviscid treatment of the expanding jet of air enriched with dissolved carbonic acid gas initially pressurised in the bottle. Solving the resulting Euler equations is facilitated through the open-source software "Clawpack". Specific enhancements allow for resolving the emerging supersonic pockets, associated with surprisingly complex shock structures, as well as the gas-stopper interaction with due accuracy. Our experimental effort provided modelling the frictional behaviour, constitutive law and reversible (de-)compression of cork. Initially, the gas expands inside the bottleneck yet sealed by the stopper, hence accelerated by the gas but decelerated by dry sliding friction. Once the stopper has passed the bottle opening, the jet rapidly assumes locally supersonic speed, where a complex shock pattern is detected. Special attention is paid to the formation and dissolution of one or even two Mach discs between the opening and the released stopper. These simulated dynamics are found to be in fairly good agreement with recent experimental findings. It also provides a first insight into the generation of the typical popping sound.Comment: Accepted by "Flow", in pres

Self-organising zooms for decentralised redundancy management in visual sensor networks

When visual sensor networks are composed of cameras which can adjust the zoom factor of their own lens, one must determine the optimal zoom levels for the cameras, for a given task. This gives rise to an important trade-off between the overlap of the different cameras’ fields of view, providing redundancy, and image quality. In an object tracking task, having multiple cameras observe the same area allows for quicker recovery, when a camera fails. In contrast having narrow zooms allow for a higher pixel count on regions of interest, leading to increased tracking confidence. In this paper we propose an approach for the self-organisation of redundancy in a distributed visual sensor network, based on decentralised multi-objective online learning using only local information to approximate the global state. We explore the impact of different zoom levels on these trade-offs, when tasking omnidirectional cameras, having perfect 360-degree view, with keeping track of a varying number of moving objects. We further show how employing decentralised reinforcement learning enables zoom configurations to be achieved dynamically at runtime according to an operator’s preference for maximising either the proportion of objects tracked, confidence associated with tracking, or redundancy in expectation of camera failure. We show that explicitly taking account of the level of overlap, even based only on local knowledge, improves resilience when cameras fail. Our results illustrate the trade-off between maintaining high confidence and object coverage, and maintaining redundancy, in anticipation of future failure. Our approach provides a fully tunable decentralised method for the self-organisation of redundancy in a changing environment, according to an operator’s preferences