Migration Policy in a Small Open Economy with a Dual Labor Market

The paper uses a two–sector efficiency–wage model to analyze the consequences of immigration for a small open economy with a dual labor market. Immigrants are characterized by an (exogenous) return probability. Legal regulations impose preferential hiring of natives or "old" immigrants. As a result, there is sectoral segregation between natives and immigrants, leading to discrimination of the type equal pay for equal work,but unequal "work." In the short run (with sector–specific capital), immigration has a positive first–order impact on natives' welfare if migration policy favors segregation through high return rates or restrictive hiring practices ("guest–worker system"). In the long run, its effect is only determined by factor intensities (2 ¥ 2 model). Finally, the improved integration of migrants yields efficiency gains and improves aggregate welfare of all residents.     

Ill-behaviour of transformation-frontiers with environmental quality versus pollution

If one looks at environmental quality N as a renewable natural resource (with its own natural dynamics) which is changed by emissions Z, then one gets a better understanding of the shape of the damage function. In the case of a logistic growth dynamics one obtains a well-shaped transformation frontier N(Z), even in a two-species natural dynamics. For a more general natural interaction in the framework of a prey-predator model one obtains the possibilities of a cusp catastrophe which makes the transformation frontier N(Z) ill-shaped for the standard arguments of economists and their most favoured environmental policy instruments.     

Habilitation von Ralf Hohlfeld

Ohne Zusammenfassung     

Formal business process engineering based on graph grammars

Designing and managing a company's specific landscape and its business processes has been identified as a great challenge for several years. Business processes are highly dynamic and distributed and can only rarely be planned, modeled and analyzed completely. For a computer-aided business process system, which supports the designing and managing process, first of all a powerful uniform formalism is necessary, where all necessary knowledge concerning company's and its processes can be represented. In this paper we will concentrate on the introduction of such a formal methodology to describe business processes, company organization structures and information technology structures in one uniform formalism. The ideas we use are mainly based on methods from graph grammars, process management, Artificial Intelligence and business process (re)engineering.     

Borda's method applied — the right to make a proposal

Borda's vote method was used by the French Academy from 1796 to 1803 when Napoleon got it abolished. In the laws and regulations of the Academy there are stipulations regarding the election of new members. The practice is demonstrated by some examples from the protocols. In fact, Borda presented two vote methods which he showed would give the same conclusion. The method which has not been in the limelight proves to be the same one as is used for selecting the best player in chess tournaments.     

Daylight saving effect

Kamstra et al. [Kamstra, M.J., Kramer, L.A., Levi, M.D., 2000. Losing sleep at the market: the daylight saving anomaly. The American Economic Review 90, 1005–1011] argue that the mean weekend return following the changes in daylight saving time is less than the mean weekend return throughout the rest of the year. Opposing studies, such as Pinegar [Pinegar, J.M., 2002. Losing sleep at the market: comment. The American Economic Review 92, 1251–1256), reason that the observed results depend upon methodology. We extend the ongoing discussions by providing further evidence for equity markets and bond markets in Germany and across Europe. We further demonstrate that the daylight saving effect does not serve as a potential rationale for the weekend effect.