Understanding the development of a regulated market approach to new psychoactive substances (NPS) in New Zealand using Punctuated Equilibrium Theory.

Punctuated Equilibrium Theory (PET) helps explain how New Zealand's Psychoactive Substances Act (PSA) policy first emerged on the political agenda and how the initial positive tone of expert support for reform shifted to a tide of popular criticism during the interim regime. However, with its emphasis on explaining agenda-setting, PET does not account for the legislative design shortcomings of the PSA.