Sunset clauses and experimental regulations: Blessing or curse for legal certainty?

Legislation is often criticized for lagging behind the evolution of society and technology. The excessive regulatory burdens, slow legislative process, and law's aversion towards legal change and uncertainty are some of the underlying reasons. However, the principle of legal certainty cannot be interpreted as a commandment imposing the immutability of legislation. Instead, a certain degree of gradual or temporary uncertainty may be necessary to ensure that laws continue to mirror society and hence grant, in the long-run, sufficient certainty. There are two candidates for this 'mission': sunset clauses and experimental legislation. These temporary legislative instruments determine the expiry of rules after a fixed period. Both instruments have been criticized and praised by the literature and case law in different countries. In this article, I examine whether and why sunset clauses and experimental legislation can be regarded as 'blessings' or 'curses' for the principle of legal certainty.