Empirical Research within Resource-Based Theory : A Meta-Analysis of the Central Propositions
Katja Nothnagel evaluates this growing body of empirical research in resource-based theory. She starts out by deriving six central propositions and then examines how these propositions have been tested empirically. Over 190 empirical resource-based papers are identified. The results of this work are evaluated through a narrative review, vote counting as well as the use of a meta-analysis. The results suggest that substantial progress has been made within the empirical part of RBT: (a) various operationalization examples on the propositions’ central constructs prove that testing RBT propositions is possible; (b) vote counting results indicate an overall positive significant impact of resources on performance with negligible results in the opposite direction of the theory; and (c) meta-analysis results show significant positive relationships. The author concludes, however, that more research is needed regarding the factor market conditions and the operationalization of resource conditions.
Competition in Marketing : Two Essays on the Impact of Information on Managerial Decisions and on Spatial Product Differentiation
In her first essay Vera Magin uses primary experimental data to explore the effects of information on marketing decisions, performance, and competition. In her second essay the author discusses several approaches to measure product differentiation in spatial contexts. In doing so, she refers to the measurement of diversity and also applies methods from disciplines like spatial statistics, forestry, and geography.

