Detecting Imprudence of ´Reliable´ Sellers in Online Auction Sites

Reputation systems deployed in popular online auction sites simply aggregate feedback about a seller´s past transactions. By studying a real auction site dataset, we infer that a non-negligible fraction of unsatisfactory transactions involve sellers with high reputation. Such a phenomenon can be interpreted by motivation theory from behaviorial science: A seller with high reputation has more business opportunities. Bad feedback for latest transactions do not immediately affect his reputation adequately to hurt business, hence he may not be as prudent as before. In this work, we propose the concept of imprudence to study and detect the inappropriate behavior of a ´reliable´ seller (i.e., the one with high reputation computed using conventional approaches). Specifically, we first identify and verify the features that influence a seller´s imprudence behavior. We then design a novel intelligent buying agent to combine these factors using logistic regression for predicting and studying the probability of imprudence of a target seller. We validate our approach using real datasets driven experiments.