This PhD thesis, entitled "Essays in Empirical Studies Based on Administrative Labour Market Data", is composed of three independent chapters, a general introduction for all three chapters at the beginning, and a brief conclusion in the end. While all three chapters are independent research...

The PhD studies different empirical methods to detect bid-rigging cartels. It shows first that simple statistical screens perform very well to detect bid-rigging infringement. Second, the econometric method of Bajari, well established in the literature, produces poor results.