Imprisonment is justified by various aims of punishment that try to influence the punished person (e.g. re-education, deterrence or incapacitation). Several approaches are available to study the effectiveness of these aims.
This article describes not only different experimental and quasi-experimental methods, their advantages and disadvantages, but also to what extent they can be used in the Czech Republic. The author first suggests an ethical and practical way how to randomly assign sanctions to offenders in order to discover the effectiveness of imprisonment.
Further, a natural experiment that originate when cases are randomly allocated to differently punitive judges is described and the author presents evidence that such natural experiment emerges in the Czech Republic. Lastly, the article discusses quasi-experimental methods and natural experiment and regression discontinuity design resulting from the amnesty of 2013 and emphasizes the limits of empirical legal research.