It took a long time – too long – before I could start writing this preface. After completing our first international comparative study in 1993, I agreed with Hugo Priemus, Johan Conijn (who together formed the Board of the OTB at the time) and Peter Boelhouwer (then my research group coordinator) about doing a PhD. That I have now finally finished it, twenty years later, is ‘thanks’ in no small measure to Hugo's 70th birthday in October 2012. Only PhD theses that have been approved before this date can still be supervised by Hugo Priemus. It is thus that I can claim the (dubious) honour of being among the last, or perhaps even the very last PhD student to be supervised by Hugo Priemus.

The whys and wherefores of the long road I travelled I will leave to psychologists to unravel. Suffice it to say that there was an unceasing stream of interesting research projects at OTB, all too tempting to pass up, and that keeping our research group up and running in the recent years of budget cuts has taken considerable time and energy. Even when it became apparent in the spring of 2012 that October was an immutable deadline, it still took several months before I got around to the putting the finishing touches on this thesis. In the end, six weeks during the summer holiday proved to be enough.

Incidentally, the long road it took to get here also had its advantages. In that time, the number of articles available to draw upon for a thesis grew. And from the final selection, it is clear to me that recent years have witnessed particularly great strides in international comparative research at OTB. While my PhD supervisors would caution me that this is not a valid selection criterion, I am pleased that the articles presented in this thesis provide a clear window on the development of the international research in which I have been involved at OTB over the last decades. And equally that the research group members with whom I have worked side by side are also ‘represented’ as co-authors in this thesis.

Professor Peter Boelhouwer and Professor Hugo Priemus have served as my PhD supervisors during this long process. It is probably fair to say that, in recent years, they have spent more time asking with quiet insistence after my progress than on supervision of the dissertation's actual content. I would like to thank both of them for their patience and for their valuable comments and criticisms on the introductory and concluding chapters of this thesis. And of course I would especially like to thank Hugo Priemus, who in 1990 secured the funding for the first international comparative study at OTB from what was then the Dutch Ministry of Housing, Spatial Planning and the Environment, and subsequently succeeded in obtaining a Bsik grant to finance the ‘System Innovation Urban and Regional Land-use and Area Development’ programme over the years from 2004 to 2009.

I am also much indebted to everyone who provided input for the various chapters of this book: Peter Boelhouwer (Chapters 2 and 3), Kees Dol (Chapter 5), Marja Elsinga (Chapters 7 and 8), Marietta Haffner (Chapters 4, 7 and 8), Joris Hoekstra (Chapter 4) and Michael Oxley (Chapters 4, 5 and 7). Beyond your contributions to the end result, I am perhaps even more grateful to you for the process of working together and the inspiring discussions along the way. I would also like to thank the other members of the Housing Policy and Housing Market Research Group for our many stimulating discussions during the group's meetings, theme group gatherings and lunch meetings. I hope to enjoy many more such discussions with you in the years to come.

Finally, many thanks to Elianne, Ineke, Joline, Joyce, Jeanet, Mary and Itziar and Dirk. Without you, this book – to which this is the preface – would never have looked as wonderful as it does.

I would like to dedicate this dissertation to my father. I am certain he would have given it a special space in his bookcase.

Willeke, Iris and Esther – I think I can safely say that I did not bother you too much with this thesis, although finishing it did of course cost Willeke a summer holiday. I promise to make it up to you.

Harry van der Heijden,

Delft, August 2012