Over the last decades, a considerable amount of empirical knowledge about the efficiency of defect-detection techniques has been accumulated. Also a few surveys have summarised those studies with different focuses, usually for a specific type of technique. This work reviews the results of empirical studies and associates them with a model of software quality economics. This allows a better comparison of the different techniques and supports the application of the model in practice as several parameters can be approximated with typical average values. The main contributions are the provision of average values of several interesting quantities w.r.t. defect detection and the identification of areas that need further research because of the limited knowledge available.