Estimation for Continuous Branching Processes

The maximum-likelihood estimator for the curved exponential family given by continuous branching processes with immigration is investigated. These processes originated from population biology but also model the dynamics of interest rates and development of the state of technology in economics. It is proved that in contrast to branching processes with discrete space and/or time the MLE gives a unified approach to the inference. In order to include singular subdomains of the parameter space we modify the MLE slightly. Consistency and asymptotic normality for the MLE are considered. Concerning the asymptotic theory of the experiments, all three properties LAQ, LAN, and LAMN occur for different submodels     

Towards expenditure rules and fiscal sanity in the euro area

The study demonstrates the key role of expenditure policies in explaining fiscal developments during EMU in the euro area, its three largest members and four “macro-imbalances” countries. It compares actual primary expenditure trends with those that would have prevailed if countries had followed neutral policies based on expenditure rules since the start of EMU. Moreover, the implications for debt trends are calculated. Results show that all sample countries except Germany applied expansionary expenditure policies already before the crisis. Consequently, expenditure and debt paths were much higher compared to a counterfactual neutral expenditure stance. Rule-based expenditure policies could have led to much safer fiscal positions much more in line with the EU's Stability and Growth Pact. An empirical analysis of the determinants of countries’ expenditure stance confirms the need for stronger fiscal rules and institutions in the euro area.     

Computation of Sharp Bounds on the Expected Value of a Supermodular Function of Risks with Given Marginals

We show that the rearrangement algorithm (RA) introduced in Puccetti and Rüschendorf (2012 Puccetti, G., Rüschendorf, L. (2012). Computation of sharp bounds on the distribution of a function of dependent risks. Journal of Computational and Applied Mathematics 236(7):1833–1840.[Crossref], [Web of Science ®] , [Google Scholar]) to compute distributional bounds can be used also to compute sharp lower and upper bounds on the expected value of a supermodular function of d random variables having fixed marginal distributions. Compared to the analytical methods existing in the literature the algorithm is widely applicable, more easily obtained and gives insight into the dependence structures attaining the bounds.     

Verbetrieblichung und betrieblicher Konflikt

Since the 1990s there is an ongoing process of decentralisation and ??Verbetrieblichung?? in German labour regulation. The opening of regional sector-level collective agreements for additional specific bargaining at the plant level is evaluated and discussed by practitioners and scholars very controversially. Critics of the decentralisation trends expect an increase of distributive conflicts inside plants and companies. The article analyses whether there are actually signs for an increase of conflicts in firm-level industrial relations in this context, and if so, under which conditions conflicts are likely to occur. Based in theoretical considerations, the article analyses the influence of different patterns of collective agreements on the incidence of conflicts and the relationship between employers and employees at firm level. Empirical data stems from a representative survey that includes interviews with management and employee representatives from German private sector companies. The data suggest some evidence on the conflict reducing function of industry-level collective agreements. Changes in a firm??s regulation structure appear to increase conflicts.     

Local principal curves

Principal components are a well established tool in dimension reduction. The extension to principal curves allows for general smooth curves which pass through the middle of a multidimensional data cloud. In this paper local principal curves are introduced, which are based on the localization of principal component analysis. The proposed algorithm is able to identify closed curves as well as multiple curves which may or may not be connected. For the evaluation of the performance of principal curves as tool for data reduction a measure of coverage is suggested. By use of simulated and real data sets the approach is compared to various alternative concepts of principal curves.     

“We will Manage It” – Did Chancellor Merkel's Dictum Increase or Even Cause the Refugee Movement in 2015?

In public and scientific debates about the dynamics of the so-called refugee crisis of 2015, there are highly controversial positions concerning the statement on August 2015 by Chancellor Merkel: “We will manage it” Did this dictum actually increase or even unleash the refugee migration towards Europe in 2015? Was Germany's governmental policy against the legal European and national frame? Based on an analysis of legal documents and public statements, the article first reconstructs the development of refugee immigration into the EU, especially to Germany, in 2015 and reviews whether the German government violated law and opened one-sided borders. Based on survey data of 4,500 refugees in 2016, it then analyses whether the Merkel dictum significantly changed the volume and the reasons why refugees decided to flee to Germany. Finally, some conclusions are drawn.     

On the distributional transform, Sklar's theorem, and the empirical copula process

We review the distributional transform of a random variable, some of its applications, and some related multivariate distributional transformations. The distributional transform is a useful tool, which allows in many respects to deal with general distributions in the same way as with continuous distributions. In particular it allows to give a simple proof of Sklar's theorem in the general case. It has been used in the literature for stochastic ordering results. It is also useful for an adequate definition of the conditional value at risk measure and for many further purposes. We also discuss the multivariate quantile transform as well as the multivariate extension of the distributional transform and some of their applications. In the final section we consider an application to an extension of a limit theorem for the empirical copula process, also called empirical dependence function, to general not necessarily continuous distributions. This is useful for constructing and analyzing tests of dependence properties for general distributions.