Regulatory competition arises where governments mutually accept quality standards in a common market. In a recent paper Hans-Werner Sinn claims that regulatory competition will be subject to market failure and lead to "competition of laxity in a sense that only the lowest possible quality standards survive regulatory competition. In this paper it is shown that these results do not need to follow when some fairly restrictive assumptions of Sinns model are relaxed. First, if his assumption of a large number of small jurisdictions is given up in favor of the assumption that a small number of larger jurisdictions compete for quality standards, then the resulting quality standards will end up above the minimum level, albeit still below an efficient level. If no subsidies are allowed in order to compensate for losses of producers working under strict quality standards, quality standards will generally converge to the level of the jurisdiction with the lowest quality preferences, but not below this level. Another assumption of Sinn is that governmental quality standards cannot better be judged by consumers than product qualities by producers. If this assumption is relaxed, regulatory competition may even be superior to a harmonized quality standard.

This article critically examines the hypothesis of Brennan and Buchanan that competition among governments in the provision of public goods can serve as a substitute for constitutional constraints on governments. Since Leviathan-type governments with free choice of tax instruments will be able to escape competitive pressure by shifting taxes to immobile factors, one could think of a rule of competition which prohibits taxes on immobile factors. Indeed, such a rule leads to a Nash-equilibrium where the tax burden lies on the mobile factor. However, net income of the citizens may or may not increase as a result from such a rule, depending on a number of variables presented in this article. A complete substitution of constitutional constraints by the rule of competition may, depending on the same variables, even decrease net income. Moreover, some potential for increases in net income may be forgone, since capital allocation and the supply of public goods will usually be inefficient in equilibrium. Finally, applying the rule in a real-world environment will be difficult and may even lead to further serious inefficiencies. For these reasons, such a rule will hardly ever be introduced. Hence, competition among governments cannot be viewed as a proper substitute for constitutional constraints. Whoever is afraid of Leviathan should thus not rely on competition among governments (alone).

Kaum ein wirtschaftspolitisches Problem ist in seiner Tragweite in der Bevölkerung so gut er-faßt wie die Bedeutung des Bevölkerungsrückgangs für die Alterssicherung in Deutschland. Es ist allgemein bekannt, daß die Gesetzliche Rentenversicherung (GRV) in Deutschland in den nächsten Jahrzehnten mit gravierenden demographisch bedingten Finanzierungsproblemen zu kämpfen haben wird. Dies ergibt sich daraus, daß die Finanzierbarkeit des nach dem Umlage-verfahren arbeitenden deutschen Rentensystems unmittelbar vom Verhältnis der beruflich akti-ven Rentenbeitragszahler zur Zahl der Rentenbezieher abhängt.

Kaum ein anderes Thema beherrschte im vergangenen Jahrzehnt die wirtschaftspolitische Diskussion so sehr wie das, was in den Medien und der wirtschaftspolitischen Literatur mit den Begriffen Standortwettbewerb, Globalisierung oder dem populären Schlagwort Wettbewerbsfähigkeit umschrieben wird. Und wenngleich die Begriffe und die dahinterstehenden Ideen und Konzeptionen mitunter schillernd sind, so beherrscht diese Thematik die wirtschaftspolitische Diskussion doch keineswegs zu unrecht. Im Gegenteil: Die Integration der Gueter- und Faktormaerkte hat die Handlungsbedingungen der Wirtschaftspolitik bereits heute entscheidend veraendert. Sie nimmt den nationalen Wirtschaftspolitiken Freiheitsgrade und zwingt ihr zunehmend neue Spielregeln auf. Eine Wirtschaftspolitik, die die veraenderten Handlungsbedingungen ignoriert, weiterhin hohe Freiheitsgrade fuer sich in Anspruch nimmt und die veraenderten Spielregeln mißachtet, fuegt der betroffenen Bevoelkerung großen Schaden zu.

. In the early 90s Mancur Olson Jr. and Martin C. McGuire developed an economic explanation of autocracy. The differentiation between roving and stationary bandits is the core of their theory. The authors claim that an "invisible hand" leads to a conversion of roving bandits into stationary bandits. In this respect, stationary bandits are "public goods providing kings" who reign peacefully. Thus, war is hardly a rational political option. However, this result stands in contradiction to the overwhelming evidence for wars in human history. Therefore, war as a political option is introduced. It is shown that the Olson/McGuire results prove to be valid only under certain circumstances

Information asymmetries between patients and physicians may provide the suppliers of medical services with the opportunity to induce demand. The thesis of "supplier-induced demand" is tested for ambulant services with two German Panel Data sets. The results show that there is no statistically significant correlation between physician-density and the demand for physician office visits. The implications of the findings are considered. Informationsasymmetrien zwischen Patienten und Ärzten ermöglichen es letzteren, die Nachfrage nach ihren eigenen Leistungen über das effiziente Ausmaß hinaus auszudehnen. Die diesen Sachverhalt be-schreibende These der "angebotsinduzierten Nachfrage" wird empirisch mit deutschen Paneldaten unter-sucht. Die Ergebnisse zeigen, daß kaum von einer statistisch signifikanten Beziehung zwischen der Arztdichte und der Inanspruchnahme ambulanter ärztlicher Leistungen gesprochen werden kann. Die möglichen wirtschaftspolitischen Implikationen werden im Schlußteil des Beitrags diskutiert.

Die vorliegende Arbeit soll einen Überblick über die politische Ökonomie des Protektionismus geben. Im folgenden Kapitel bestätigt die kritische Überprüfung der im Rahmen der traditionellen Außenhandelstheorie vorgetragenen Argumente für protektionistische Eingriffe die grundsätzliche Überlegenheit des Freihandelsprinzips. Die Existenz von Handelshemmnissen, die aus wohlfahrtstheoretischer Sicht nicht zu rechtfertigen sind, kann durch Einbeziehung des politischen Marktes für Protektionen erklärt werden.

The realization of integrated-optic broadband wavelength devision multiplexer for separation of 1.31µm and 1.55µm wavelength window is demonstrated based on the well known arrayed waveguide structure. Broadband characteristic with passband greater than 100nm is achieved by using low diffraction order (m = 1, 2). The number of arrayed waveguides is W = 13 and W= 7 respectively. Structure parameters especially those for the star coupler region are derived by use of the transfer-matrix formalism for layered media and the wide-angle finite difference beam propagation method. Prototypes of these structures where realised as doped silica on silicon substrate by using standard plasma enhanced chemical vapor deposition (PECVD) and reactive ion etching (RIE) techniques. The waveguide structure is based on a 7x7µm waveguide core with refractive index difference Dn = 0.005 with reference to a 20µm buffer and cladding layer. Phosphor and Boron were used as dopands of each silica layer to achieve proper adjustment of phys ical layer properties, i.e. refractive index and transformation temperature. Codopand Boron is used to open a selective thermal postprocessing of deposited layers to overcome inhomogeneous PECVD cladding layer deposition on the RIE structured waveguide

The present work investigates the interaction between buckminsterfullerene molecules (C60) and silicon surfaces as well as the influence of buckminsterfullerenes on metal/silicon interfaces. The knowledge about the mechanism of surface/molecule interaction between the technologically important semiconductor Si and C60 molecules may lead to new applications of fullerenes. In this context the present study compares the adsorption and the growth mechanisms as well as the desorption of C60 molecules which were evaporated onto well-prepared Si(111)-7x7-, Si(111):H-1x1- and Si(111):Ag-(sqrt(3) x sqrt(3))R30°-surfaces using Auger electron spectroscopy (AES), low-energy electron diffraction (LEED) under ultra-high vacuum conditions. The electronic structure of C60-covered Si(111)-7x7-, Si(111)-1x1-, Si(111):H-1x1-and Si(111):Ag-(sqrt(3) x sqrt(3))R30°-surfaces was investigated using ultraviolet and X-ray photoelectron spectroscopy (UPS, XPS). From these experiments the molecule/surface interaction mechanisms can be identified. Crystalline C60 is a new semiconductor material. Therefore, evaporating C60 onto Si surfaces builds up a semiconductor heterostructure. The electronic properties of this heterostructure are characterized by the band discontinuities at the C60/Si interface. Using UPS and XPS the valence-band discontinuity at this semiconductor/semiconductor interface were determined. Additionally, metal/Si contacts were produced on initially clean silicon surfaces which were covered with distinct amounts of C60 before Ag-, Pb- or Pd-contacts were evaporated. The transport properties of these contacts were studied by current-voltage-chracteristics to determine the influence of C60-layers on the Schottky barrier heights of the metal/Si contacts.

Metamagnets have been playing an important role as model systems in the physics of phase transitions for 30 years. Especially the isolating substances FeCl2 and FeBr2 have attracted much interest both in experimental and theoretical physics. In this thesis we focus on experimental investigations of Fe1-xMgxBr2 with x = 0 and 0.05. By SQUID-magnetometry, SQUID-susceptometry, elastic neutron scattering and calorimetry we studied the magnetic phase boundaries and especially the recently found new phase transition at H=H1(T) (Aruga Katori et al. 1996). Also we arrived to a physical understanding of the non-critical fluctuations at H=H-(T) in terms of a smeared 2-dimensional phase transition of the spin down sublattice.