What level of legal protection, if any, should be allocated to inventions falling below the conventional criteria for patentability, also known as sub-patentable inventions, in order to best stimulate innovation? This is the central research question which is pursued by in the publication “Innovation without Patents – Harnessing the Creative Spirit in a Diverse World.” This question involves a balancing exercise between the need to incentivise research through offering legal protection and the need for a large public domain to encourage innovation which may be restricted by excessive protections. This work provides an international comparative study of the empirical findings on the operation of various systems of protection for sub-patentable inventions in a number of regions throughout the world. The central research question is considered in a holistic manner, involving a discussion of the economic, industry specific and legal factors which should be taken into account by governments, especially those of developing countries when deciding on what protections, if any to adopt.