In January 2006, the Dutch Association of Industry-wide Pension Funds (VB) told us about their plan to prepare a book on solidarity in collective pension systems. We were intrigued by this topic, both because of our - terest in the pension sector and because of the connection with solidarity in a cost-benefit approach. After some discussions with VB director Peter Borgdorff, we decided to start a project with leading scholars and prac- tioners, which was to result in a book. We hoped that the researchers could investigate the extent of value transfers within collective pension funds, so that...