Voluntary contributing in a neighborhood public good game: An experimental study

In repeated Public Good Games contributions might be influenced by different motives. The variety of motives for deciding between (more or less) free-riding probably explains the seemingly endless tradition of theoretical and experimental studies of repeated Public Good Games. To more clearly distinguish the motives, we try to enrich the choice set by allowing players not only to contribute but also to locate their contribution to one of the player positions. The location choice affects what individual players gain, but not the overall efficiency of contributing, and allows for discrimination, e.g., rewarding and sanctioning co-players differently. Our experimental results show that adding location choice promotes voluntary cooperation, although discrimination itself has no signifficant effect on behavior. --Public Good Game,Neighborhood,Cooperation,Experimental Analysis

Increasing the {\nu} = 5 / 2 gap energy: an analysis of MBE growth parameters

The fractional quantized Hall state (FQHS) at the filling factor {\nu} = 5/2 is of special interest due to its possible application for quantum computing. Here we report on the optimization of growth parameters that allowed us to produce two-dimensional electron gases (2DEGs) with a 5/2 gap energy up to 135 mK. We concentrated on optimizing the MBE growth to provide high 5/2 gap energies in "as-grown" samples, without the need to enhance the 2DEGs properties by illumination or gating techniques. Our findings allow us to analyse the impact of doping in narrow quantum wells with respect to conventional DX-doping in AlxGa1-xAs. The impact of the setback distance between doping layer and 2DEG was investigated as well. Additionally, we found a considerable increase in gap energy by reducing the amount of background impurities. To this end growth techniques like temperature reductions for substrate and effusion cells and the reduction of the Al mole fraction in the 2DEG region were applied

Demography and Innovative Entrepreneurship

Demographic change will be one of the major challenges for economic policy in the developed world in the next decades. In this article, we analyze the relationship between age structure and the number of startups. We argue that an individual’s decision to start a business is determined by his or her age and, therefore, that a change in a region’s age distribution affects the expected number of startups in the region. Using German regional data, we estimate a count-data model and find that the expected number of startups is positively influenced by the fraction of individuals of working age—20–64 years old. A more detailed analysis of the working-age distribution suggests that startups in knowledge-based (high-tech) manufacturing industries are affected by changes in this distribution whereas firms in other industries are not. In particular, increases in the fraction of individuals in the 20–30 age range and individuals in the 40–50 age range have a positive effect on the number of high-tech startups.demography, age distribution, entrepreneurship, innovation, region

Ungarns Wirtschaftswachstum von Ungleichgewichten geprägt: ein erneutes Problem mit dem Zwillingsdefizit?

Der Artikel beschäftigt sich mit dem Problem Ungarns, auf einen makroökonomisch stabilen Wachstumspfad einzuschwenken. Seitdem im Jahre 1994 die Entwicklungen des Haushaltsbudgets und der Leistungsbilanz das Land an den Rand einer Krise brachte, wird der weiteren Entwicklung des ungarischen “Zwillingsdefizits“ besondere Beachtung geschenkt. Die Analyse der sich seit 1998 wieder intensivierenden Instabilitäten deutet auf neue Ursachen, welche in ihrer Wirkungsdauer meist nur beschränkt sind und in der Wirtschaftsplanung weitgehend antizipiert wurden. Damit ist aus heutiger Sicht eine erneute krisenhafte Entwicklung in Ungarn nicht zu erwarten

The Effect of Luxury Taxes on Competitive Balance, Club Profits, and Social Welfare in Sports Leagues

This paper provides a game-theoretic model of a professional sports league and analyzes the effect of luxury taxes on competitive balance, club profits and social welfare. We show that a luxury tax increases aggregate salary payments in the league as well as produces a more balanced league. Moreover, a higher tax rate increases the profits of large-market clubs, whereas the profits of small-market clubs only increase if the tax rate is not set inadequately high. Finally, we show that social welfare increases with a luxury tax.Sports League, Luxury Tax, Social Welfare, Competitive Balance

Tunable Charge Detectors for Semiconductor Quantum Circuits

Nanostructures defined in high-mobility two-dimensional electron systems offer a unique way of controlling the microscopic details of the investigated device. Quantum point contacts play a key role in these investigations, since they are not only a research topic themselves, but turn out to serve as convenient and powerful detectors for their electrostatic environment. We investigate how the sensitivity of charge detectors can be further improved by reducing screening, increasing the capacitive coupling between charge and detector and by tuning the quantum point contacts' confinement potential into the shape of a localized state. We demonstrate the benefits of utilizing a localized state by performing fast and well-resolved charge detection of a large quantum dot in the quantum Hall regime

Demography and innovative entrepreneurship

Demographic change will be one of the major challenges for economic policy in the developed world in the next decades. In this article, we analyze the relationship between age structure and the number of startups. We argue that an individual's decision to start a business is determined by his or her age and, therefore, that a change in a region's age distribution affects the expected number of startups in the region. Using German regional data, we estimate a count-data model and find that the expected number of startups is positively influenced by the fraction of individuals of working age 20 64 years old. A more detailed analysis of the working-age distribution suggests that startups in knowledge-based (high-tech) manufacturing industries are affected by changes in this distribution whereas firms in other industries are not. In particular, increases in the fraction of individuals in the 20 30 age range and individuals in the 40 50 age range have a positive effect on the number of high-tech startups

Course and Outcome of Bacteremia Due to Staphylococcus aureus: Evaluation of Different Clinical Case Definitions

In a retrospective survey of patients hospitalized in the University Hospital of Basel, Switzerland, the course and outcome of 281 cases of true bacteremia due to Staphylococcus aureus over a 7-year period were analyzed. The main purpose was to evaluate different case definitions. In 78% of cases the source of bacteremia was obvious; vascular access sites (27%) and wounds (10%) were the most common sources. Metastasizing foci were more common in cases of primary vs. secondary bacteremia (P < .001). The incidence of endocarditis was higher in cases in which no portal of entry was defined (P < .03). The overall mortality rate was high at 34% partly because of inappropriate initial antibiotic therapy. With the introduction of an infectious disease service at the hospital, the fraction of misjudged results of blood culture diminished 2.5-fold. Among the differently defined cases, the mortality rate was significantly higher for cases of complicated vs. uncomplicated bacteremia (P < .01), for cases of primary vs. secondary bacteremia (P = .05), and for patients with endocarditis or other secondary foci (P < .001). Since only one methicillin-resistant strain was isolated, multiresistant staphylococci were not a problem in the hospital. Different case definitions allowed the detection of patients at increased risk for complications and death. In the treatment of sepsis with no evident focus, initial antimicrobial therapy should include the use of agents with antistaphylococcal activit