Price comparison services are being used by more and more internet users worldwide tocompare prices of (online-)suppliers. The characteristics of price comparison services differinternationally. Not only are they different in the reference to their scope of work. Also with regard tothe technical...

This paper proposes a model of urban agglomeration in conjunction withimperfect competition and endogenous product R&D of firms. The qualityof differentiated manufacturing goods is a result of R&D services providedby research firms. Sectoral interactions are subject to spatially...

This paper gives an overview of different methodologies related to value chain analysis in thecontext of environment and trade research. Four major fields of methodologies are identified:Accounting of input-output flows, general equilibrium models, econometrics, and globalcommodity chain...

We develop a Wald type test to distinguish between long memory and ESTARnonlinearity by using a directed-Wald statistic to overcome the problem of restricted parametersunder the alternative. The test is derived from two basic model specificationswhere the first is the standard model based on an...

This paper introduces wealth-dependent time preference into a simplemodel of endogenous growth. The model generates adjustment dynamics in linewith the historical facts on savings and economic growth in Europe from the HighMiddle Ages to today. Along a virtuous cycle of development more wealth...

We have developed a new test against spurious long memory based on the invarianceof long memory parameter to aggregation. By using the local Whittleestimator, the statistic takes the supremum among combinations of paired aggregatedseries. Simulations show that the test performs good in nite...

Als Folge der jüngsten gesundheitspolitischen Reformen in Deutschland scheint ein Wan-del in der HIV-Versorgungsstruktur unumgänglich. Vor diesem Hintergrund widmeten sich im November 2008 unterschiedliche Interessenvertreter in einem Workshop der Identifikation und Diskussion zukünftiger...