Can impact assessments tame legislative drift? Event history analysis of modifications of laws across Europe

Abstract

Laws should endure and change only if assumed benefits don't materialize over time. Yet frequent modifications of laws shortly after their enactment distort this compromise between stability and change. While, Impact Assessments (IAs) are designed to improve the quality of legislation, we know little about IAs' impact on legal stability post-enactment. We fill this gap by analysing whether the ex-ante application of IAs influences the incidence and frequency of legal modifications. The analysis is based on a complete dataset of more than 2500 laws in France, Hungary, Italy, and the UK between 2006 and 2012. We apply a comparative event history analysis to account for both first and subsequent modifications. We find across-the-board that IAs are associated with legal stability. IAs are predicted to have the largest effect when political power changes both in terms of seat shares and party ideology, suggesting that IAs can, to some degree, tame legislative drift.