Time Series Properties of the German Monthly Production Index

The production index is an important indicator for assessing the cyclical state of the economy. Unfortunately, the monthly time series is contaminated by many noisy components like seasonal variations, calendar and vacation effects. Only part of those nuisance components are explicitly considered in the seasonal adjustment procedures used by statistical agencies. In this paper, we propose a more flexible specification for the seasonal and working day effects and introduce an indicator for the summer vacations effect. We allow for time-varying parameters and show that the resulting Unobserved Components Model delivers more reliable results for the adjusted series.production index, seasonal adjustment, working day effect, business cycles, unobserved components models

Labour Market Institutions and Unemployment. An International Comparison

This paper deals with the effects of labour market institutions on unemployment in a panel of 19 OECD countries for the period 1960 to 2000. In contrast to many other studies, we use long time series and analyze cyclically adjusted trend values of the unemployment rate. Our novel contribution is the estimation of panel models where we allow for heterogeneous effects of institutions on unemployment. Our main results are that on the average a tighter employment protection, a higher tax burden on labour income and a more generous unemployment insurance system increase, whereas a higher centralization of wage negotiations decreases unemployment. The strength of the effects differs considerably between countries.employment protection, labour market institutions, unemployment, international comparison

Estimating the Output Gap Using Business Survey Data - A Bivariate Structural Time Series Model for the German Economy

This paper deals with the estimation of the output gap. We use uni- and bivariate unobserved components models in order to decompose the observed German GDP-series into trend, cycle and seasonal components. The results show that using the ifo business assessment variable as an indicator for the cycle the estimation of the output gap is much more precise and out-of-sample forecasts exhibit smaller prediction errors.Output gap, unobserved component models, survey data

Labour Market Institutions and Employment Thresholds. An International Comparison

This paper deals with the effects to labour market institutions on labour market performance. We analyse the employment threshold (the minimum growth rate necessaryto keep employment constant) which is an indicator for the labour intensity of production. We show for 17 OECD countries for the period 1971 to 2002 that the strictness of employment protection, the extent of wage bargaining co-ordination and the tax wedge reduce the labour intensity of production and raise the employment threshold.Employment protection, labour market institutions, labour demand, internationaln comparison.

Labour Market Institutions and the Employment Intensity of Output Growth. An International Comparison

This paper deals with the effects of labour market institutions on labour market performance. We analyse as an indicator for the labour intensity of output growth the employment threshold (the minimum growth rate of output necessary to keep employment constant). We show for a sample of 17 OECD countries for the period 1971 to 2002 that the strictness of employment protection raises the employment threshold in all econometric specifications. A higher wage bargaining coordination and a higher tax wedge reduce also the labour intensity of production, although the effects are not significant in all econometric specifications.employment protection, labour market institutions, labour demand, international comparison, employment threshold

Vertical Structure and Turbulent Saturation Level in Fully Radiative Protoplanetary Disc Models

We investigate a massive ($\varSigma \sim 10000 g cm^{-2}$ at 1 AU) protoplanetary disc model by means of 3D radiation magnetohydrodynamics simulations. The vertical structure of the disc is determined self-consistently by a balance between turbulent heating caused by the MRI and radiative cooling. Concerning the vertical structure, two different regions can be distinguished: A gas-pressure dominated, optically thick midplane region where most of the dissipation takes place, and a magnetically dominated, optically thin corona which is dominated by strong shocks. At the location of the photosphere, the turbulence is supersonic ($M \sim 2$), which is consistent with previous results obtained from the fitting of spectra of YSOs. It is known that the turbulent saturation level in simulations of MRI-induced turbulence does depend on numerical factors such as the numerical resolution and the box size. However, by performing a suite of runs at different resolutions (using up to 64x128x512 grid cells) and with varying box sizes (with up to 16 pressure scaleheights in the vertical direction), we find that both the saturation levels and the heating rates show a clear trend to converge once a sufficient resolution in the vertical direction has been achieved.Comment: 11 pages, 10 figures, accepted for publication in MNRA

Parametric study of modern airship productivity

A method for estimating the specific productivity of both hybrid and fully buoyant airships is developed. Various methods of estimating structural weight of deltoid hybrids are discussed and a derived weight estimating relationship is presented. Specific productivity is used as a figure of merit in a parametric study of fully buoyant ellipsoidal and deltoid hybrid semi-buoyant vehicles. The sensitivity of results as a function of assumptions is also determined. No airship configurations were found to have superior specific productivity to transport airplanes

Time Series Properties of the German Monthly Production Index

The production index is an important indicator for assessing the cyclical state of the economy. Unfortunately, the monthly time series is contaminated by many noisy components like seasonal variations, calendar and vacation effects. Only part of those nuisance components are explicitly considered in the seasonal adjustment procedures used by statistical agencies. In this paper, we propose a more flexible specification for the seasonal and working day effects and introduce an indicator for the summer vacations effect. We allow for time-varying parameters and show that the resulting Unobserved Components Model delivers more reliable results for the adjusted series