Effective patent life is lost in pharmaceuticals because of the lengthy tim
e periods required for clinical trials and regulatory approval. A 1984 US l
aw restores some of this lost patent time, while also facilitating generic
competition when patents expire. This paper examines this law and the effec
ts of other policy developments on market exclusivity times in pharmaceutic
als. It also performs simulation analyses on how proposed legislative refor
ms would impact on future new drug introductions.