During the last decades, the number of ICT related patents has increased considerably. In association with a great fragmentation in IP rights, the increasing number of patents has generated a series of potentially problematic consequences. Patent thickets, royalty stacking, the emergence of patent assertion entities, increased patent litigation – in particular around standard essential patents – and the difficulties in the definition of fair, reasonable and non-discriminatory (FRAND) licensing terms are among the most debated issues in the literature that we review in this paper. We devote a specific section of our survey to patents involving software products, where the above problems are amplified by the high level of abstraction of computer algorithms. In our analysis we mix theoretical and empirical arguments with a more policy-oriented reasoning. This allows us to better position the different issues in the relevant political and economic context.
