Wettbewerbsmanipulationen in Online-Auktionen
The competitive bidding process in online auctions is influenced by different types of manipulations that are difficult to detect. The thesis contributes to the development of identification methods of these manipulation types and shows their frequency in real online auctions. The identification methods consist of a combination of appropriate indications that are aggregated on the basis of statistical tests. Simulation studies are conducted to verify the suitability of indications and identifications methods developed. The fundament of the simulations is an artificial auction market that is affected by different types of manipulation. The application of the developed identification methods to real auction data shows the frequency of occurrence of different types of competition manipulations in practice. As a key finding of the empirical analysis, the manipulation type of Shilling can be exposed. Shilling means the bidding of sellers in their own auctions. The study suggests that at least every fifth professional seller conducts shilling bids.
