28 April 2026
Economic Policy StudyThe Impact of Data Retention on Crime
Photo: UHH/Sebastian Engels
Data retention requires telecommunications providers to store user data—such as traffic and location information—for several months without cause, in order to pass it on to investigative authorities when necessary and upon official authorization. Opponents view this as a significant infringement on fundamental rights, such as the right to privacy of telecommunications or data protection. Consequently, a corresponding law from 2007 was overturned by the Federal Constitutional Court in 2010. The current federal government is working on a new draft law that provides for the three-month storage of connection data.
“Ultimately, a weighing of the pros and cons will decide the fate of such a law,” says Prof. Dr. Wolfgang Maennig of the University of Hamburg, assessing the situation. “Among the disadvantages, in addition to the restriction of data protection and privacy rights, are the costs incurred by companies required to store the data. One advantage, however, is the reduction in criminal offenses, particularly in the economic sector.”
For a recent study, the professor of Economic Policy analyzed the development of crime rates in eleven EU countries that had introduced data retention systems, at least temporarily. Maennig and his co-author Dr. Stefan Wilhem used modern statistical methods for this purpose. These methods isolate the effects of variables that influence crime rates, such as a country’s economic situation, its unemployment rate, or the age structure of its population. This allowed them to clearly identify the effects of the legislative changes. The researchers then subjected their results to several robustness tests.
The result: property crimes, which account for about half of all crimes, decreased by seven to eight percent two years after the introduction of data retention. These include, for example, offenses such as theft or burglary, but also fraud offenses such as embezzlement or identity theft.
However, no significant effect on violent crime was observed.
“The effect on property crimes, however, is only partly attributable to increased clearance rates. These rose only slightly following the enhanced data retention. Instead, deterrent effects dominate. Perpetrators apparently became more afraid of being caught,” explains Maennig.
Whether this would remain the case in the long term cannot be predicted based on the study. “Our results suggest, however, that potential offenders gradually react to policy changes and develop new routines or tactics with a certain time lag. This may also mean that the initial crime-deterring effect of such laws diminishes again over time,” says Maennig.
(This content was translated automatically)