Abbau der Langzeitarbeitslosigkeit: Der Weg ist steinig und schwer

The German labour market has recently performed well. But the persistence of unemployment is still considerable. The outflows from long-term unemployment into employment have not significantly increased in recent years. This is due to various individual risks of the long-term unemployed, such as low education, low qualification, old age and weak health. Analyses show that previous reductions in long-term unemployment levels were attained by lowering new inflows. These findings indicate that comprehensive early prevention measures are needed. In addition, more individualised and thorough employment services are required.     

Techno-ökonomische Bewertung von Energie-Autarkie für die Energieversorgung von Einfamilienhäusern

Many consumers currently follow the idea of energy self-sufficiency and try to contribute to meet their energy needs in order to become independent and self-sufficient from the central power supply system. In order to achieve load-oriented energy self-sufficiency the provision of energy must cover the full energy demand at any time. Against this background, in this paper the costs and potentials of a load-oriented energy self-sufficiency of single-family homes are analysed. Thereby it is differentiated between electricity-, heat- and energy self-sufficiency. The modelling is carried out with the simulation environment ?Polysun Designer“ which allows a high temporal dynamic simulation of the annual energy demand and supply.The results show that, within the investigated supply variations, the highest levels of energy self-sufficiency can be achieved by an energy supply system completely based on electricity using a combination of PV; heat pump and battery storage. Depending on the building standard, a maximum of 45 (existing buildings) and 71?% (new buildings) of the building’s energy demand can be covered with renewable energy. The economic evaluation however has shown that under present conditions, none of the investigated supply variants can compete with conventional energy supply (public grid connection + gas condensing boiler).     

Confidence sets for the date of a single break in linear time series regressions

This paper considers the problem of constructing confidence sets for the date of a single break in a linear time series regression. We establish analytically and by small sample simulation that the current standard method in econometrics for constructing such confidence intervals has a coverage rate far below nominal levels when breaks are of moderate magnitude. Given that breaks of moderate magnitude are a theoretically and empirically relevant phenomenon, we proceed to develop an appropriate alternative. We suggest constructing confidence sets by inverting a sequence of tests. Each of the tests maintains a specific break date under the null hypothesis, and rejects when a break occurs elsewhere. By inverting a certain variant of a locally best invariant test, we ensure that the asymptotic critical value does not depend on the maintained break date. A valid confidence set can hence be obtained by assessing which of the sequence of test statistics exceeds a single number.     

Firms as Realizations of Entrepreneurial Visions

abstract    In the debate on why firms exist, the question of who chooses between firms and markets and on what basis is rarely addressed. This paper argues that the choice is a core element of the entrepreneurial pursuit of visions or conceptions of business opportunities. To successfully organize resources into the envisioned businesses – be it via firms or markets – resource owners must be coordinated on the entrepreneur's conception of the business and be motivated to perform properly. To solve the dual problem, the organizational form of the firm offers the entrepreneur unique advantages not feasible under the organizational form of markets.     

Capacity Choices and Price Competition in Experimental Markets

We report on experimental duopoly markets with heterogeneous goods. In these markets, sellers first choose capacities and then prices. While capacities remain fixed for either five or ten periods, prices have to be chosen in every period. The experiments starts with two sets of exogenously predetermined capacities. Independently of the distribution of capacities is, a unique pure-strategy in prices is subgame perfect. In equilibrium, capacities should correspond to the Cournot prediction. Given capacities, price-setting behavior is in general consistent with the theory. Average capacities converge above the Cournot level. Capacities converge at the industry level but are somewhat dispersed. Sellers rarely manage to cooperate.     

Joint Production and the Structure of Technology: A Generalization

In this paper, we have a peek inside the black box of technology in an attempt to get a better understanding of the concept of joint production. We introduce the notion of input and output subtechnologies; these are then used as building blocks to define various types of production processes, either joint or nonjoint. Thus, in the 2×2 case, we are able to identify up to 36 different production structures, some of which are well known, but most of which are new. These are all described in the primal quantity space as well as in the dual price space. Comparative statics results for the 2×2 joint production process are derived.