This report addresses the responses related to scarcity rents and airport charges. The Commission has asked ITF/SEO to provide evidence on scarcity rents in the London airport system. Different reports submitted in response to the Commission’s consultation make different assumptions on the way airlines either absorb or pass through aero-charges and whether or not airlines benefit from scarcity rents at an airport. The arguments comprised in submissions to the Commission relating to scarcity will be assessed objectively using economic theory. This will help the Commission to give validity or invalidate the arguments put forward on scarcity rents and their potential impact on the estimated results.