Experimental regulations and regulatory sandboxes: Law without order

This article argues that the poor design and implementation of experimental regulations and regulatory sandboxes can have both methodological and legal implications. First, the internal validity of experimental legal regimes is limited because it is unclear whether the verified positive or negative results are the direct result of the experimental intervention or other circumstances. The limited external validity of experimental legal regimes impedes the generalization of the experiment and thus the ability to draw broader conclusions for the regulatory process. Second, experimental legal regimes that are not scientifically sound make a limited contribution to the advancement of evidence-based lawmaking and the rationalization of regulation. Third, methodological deficiencies may result in the violation of legal principles (e.g., legality, legal certainty, equal treatment, proportionality) which require that experimental regulations follow objective, transparent, and predictable standards. <br><br>This article contributes to existing comparative public law and law and methods literature with an interdisciplinary framework which can help improve the design of experimental regulations and regulatory sandboxes. This article starts with an analysis of the central features, functions, and legal framework of these experimental legal regimes. It does so by focusing on legal scholarship, policy reports, and case law on experimental regulations and regulatory sandboxes from France, United Kingdom, and The Netherlands. While this article is not strictly comparative in its methodology, the three selected jurisdictions illustrate well the different facets of experimental legal regimes. This article draws on social science literature on the methods of field experiments to offer novel methodological insights for a more transparent and objective design of experimental regulations and regulatory sandboxes.