Are Good Industrial Relations Good for the Economy?

Using international data, we investigate whether the quality of industrial relations matters for the macro economy. We measure industrial relations inversely by strikes Ð which proxy we cross-check with an industrial relations reputation indicator Ð and our macro performance indicator is the unemployment rate. Independent of the role of other institutions, good industrial relations do seem to matter: greater strike volume is associated with higher unemployment. But these results apply in cross section. Holding country effects constant, the sign of the strikes coefficient is abruptly reversed. Although it does not seem to be the case that the line of causation runs from unemployment to strikes once we control for the endogeneity of strikes, it is also the case that support for the strikes proxy for industrial relations quality is much eroded.strikes, industrial relations quality, unemployment, labor market institutions, cross-country data

Rent Seeking at Plant Level: An Application of the Card-De la Rica Tenure Model to Workers in German Works Councils

Low-skilled workers enjoy a large wage advantage in German works council establishments. Since job tenure is also longer for these workers, one explanation might be rent-seeking. If the premium is a compensating wage differential (or a return to unmeasured ability), it should not lead to higher tenure; whereas if it is (partly) rent, lower quits should lead to longer tenure at plants with works councils. Our analysis uses the Card and de la Rica (2006) tenure model, and although the association between skill level and the works council tenure gap is positive it fails to achieve statistical significance in a single equation framework. However, running the tenure equation for separate skill quintiles, we find that those with the highest wage premium have the greatest tenure. As a result, although we cannot be certain that the works council wage mark-up of low-skilled workers is necessarily a non competitive rent, the observed pattern of job tenure across different skill subsamples is not after all inconsistent with rent-seeking behavior.

German Works Councils and the Anatomy of Wages

This paper provides a comprehensive examination of the effect of German works councils on wages, using matched employer-employee data from the German LIAB for 2001. In general, we find that works councils are associated with higher earnings, even after accounting for worker and establishment heterogeneity. At this level, the works council premium exceeds the collective bargaining mark-up, and is modestly higher in the presence of collective bargaining once we account for worker selection into the two institutions. More specifically, works councils do seem to benefit women relatively and to build on collective bargaining in this regard. They also seem to favor foreign, east-German, and service-sector workers although the effects of collective bargaining are not always reinforcing. The evidence from quantile regressions suggests that only in conjunction with collective bargaining is the narrowing influence of works councils really clear-cut. The above findings pertain to workers in all plants. Once we consider smaller establishments with 21-100 employees, however, each of these results is further qualified, beginning with the effect on wage levels where premia are now only observed in conjunction with collective bargaining.works councils, collective bargaining coverage, matched employer-employee data, wages, wage distribution.

Interacting spin 0 fields with torsion via Duffin-Kemmer-Petiau theory

Here we study the behaviour of spin 0 sector of the DKP field in spaces with torsion. First we show that in a Riemann-Cartan manifold the DKP field presents an interaction with torsion when minimal coupling is performed, contrary to the behaviour of the KG field, a result that breaks the usual equivalence between the DKP and the KG fields. Next we analyse the case of Teleparallel Equivalent of General Relativity Weitzenbock manifold, showing that in this case there is a perfect agreement between KG and DKP fields. The origins of both results are also discussed.Comment: 10 pages, no figures, uses REVTEX. Changes in the presentation, minor misprints and one equation corrected. References updated. To appear in General Relativity and Gravitatio

Estimação e Compensação de Atritos em um Pêndulo Invertido

O pêndulo invertido é um sistema mecânico subatuado, inerentemente instável em malha aberta, de dinâmica não linear, sendo uma referência clássica para o estudo de problemas de controle. A motivação por trás deste interesse é o crescente número de aplicações de posicionamento preciso em sistemas mecânicos. A aplicação de técnicas de controle sem levar em consideração o atrito presente pode produzir ciclos limite. Neste trabalho, métodos de modelagem, quantificação e compensação de atrito são analisados e aplicados ao pêndulo invertido. Técnicas recentemente propostas na literatura são adaptadas para o sistema em estudo. Modelos de atrito de Coulomb, Karnopp e LuGre são discutidos e são analisados métodos para obtenção de seus parâmetros via identificação em malha aberta e em malha fechada e via quantificação a partir do ajuste de elipses a dados de entrada versus saída. O atrito quantificado pelos diferentes modelos são comparados. Estes modelos são utilizados para compensar o atrito presente no carrinho do pêndulo. Os métodos de compensação não baseados em modelo denominados reforço constante e knocker são também aplicados. Seus desempenhos são avaliados e comparados usando três índices de desempenho, através da aplicação a um pêndulo real

Performance of dynamical decoupling in bosonic environments and under pulse-timing fluctuations

We study the suppression of qubit dephasing through Uhrig dynamical decoupling (UDD) in nontrivial environments modeled within the spin-boson formalism. In particular, we address the case of (i) a qubit coupled to a bosonic bath with power-law spectral density, and (ii) a qubit coupled to a single harmonic oscillator that dissipates energy into a bosonic bath, which embodies an example of a structured bath for the qubit. We then model the influence of random time jitter in the UDD protocol by sorting pulse-application times from Gaussian distributions centered at appropriate values dictated by the optimal protocol. In case (i) we find that, when few pulses are applied and a sharp cutoff is considered, longer coherence times and robust UDD performances (against random timing errors) are achieved for a super-Ohmic bath. On the other hand, when an exponential cutoff is considered a super-Ohmic bath is undesirable. In case (ii) the best scenario is obtained for an overdamped harmonic motion. Our study provides relevant information for the implementation of optimized schemes for the protection of quantum states from decoherence.Comment: 8 pages, 5 figure