Interaction effects capture the impact of one explanatory variable x1 on the marginal effect of another explanatory variable x2. To explore interaction effects, so-called interaction terms x1x2 are typically included in estimation specifications. While in linear models the effect of a marginal...

In Germany, competitive franchising is increasingly being used to procure passenger railway services that were previously provided by a state monopolist. This paper analyzes 77 tenders that differ with respect to network size, service frequency, contract duration and the proximity to other lines...

Following the discussion on reurbanization (changing intra-regional migration patterns), our research project treats transport-related consequences of this spatial development in German city regions. The hypothesis is that reurbanization bears potential to spread environmentally friendly ways of...

The equilibrium conditions for an economic system that produces output with several factors of production and which is subject to technological constraints are derived. Optimization of either output minus cost or integrated utility yields the conditions that output elasticities must be equal to...

In der vorliegenden Arbeit werden verschiedene fundamentale Prognosemodelle für die Preise von stündlichen Day-Ahead Elektrizitätskontrakten auf den deutschen Markt geschätzt und getestet. Dabei wird ein breites Spektrum an fundamentalen Variablen berücksichtigt, um den spezifischen...