The essential facility doctrine lies at the core of telecoms regulation since its very first steps in the United States and in the European Union. Later, the doctrine spread around the world and currently stands as a key pillar of the liberalization efforts underway in several countries. However, the concept of essential facility is a very dynamic one in the telecoms field, which makes it hard for regulators and regulated stakeholders to strike the right balance between incentives to invest in new infrastructure and securing access-based competition in the short run. Experiment such as the ''stepping stones'' approach in the US and the ''investment ladder'' approach in the EU have led to very mixed results, in the US, the FCC eventually aba...