Threats of punishment are supposed to deter potential criminals from committing crimes. Numerous empirical investigations have tried to examine the correctness of this theory with varying results. The meta-analysis undertaken in this study attempts to determine why there are so many differing findings; the analysis reveals that first evaluations indicate that the methods of research have an influence on the results and that a possible deterring effect of the penal law can only be covered reasonably with a very differentiating model. Not all criminal acts can be influenced by deterrence. It appears that the most significant deterrent effects can be achieved in cases of minor crime, administrative offenses, and infringements of informal social norms. In the case of homicide, the meta-analysis does not indicate that the death penalty has a deterrent effect. Data were collected from 700 studies with 7,822 effect estimates. Tables, diagrams, and references