Abstract
This article summarizes the results of a study of the Netherlands Institute for Transport Policy Analysis (KiM) on costs and benefits of cooperation between port authorities (Wortelboer en Kolkman, Samenwerking tussen Zeehavens, December 2008). The article elaborates on the question whether, and if so, how, cooperation between port authorities can contribute to our societal welfare and what role the national government can play in promoting this cooperation.