Next to a challenging research topic there are many other things that contribute to a
pleasant Ph.D. period. This is a good time to thank the human factors. First of all,
I would like to thank my promotor and co-promotor, Philip Hans Franses and Richard
Paap. Not only are they pleasant people to work with, they have been very important in
my development as a researcher and for the research itself. Philip Hans is a never ending
source of ideas and inspiration. Many of these ideas were related to my thesis, others
were on completely different topics and provided a welcome distraction. Philip Hans also
aroused my interest in other research fields, ranging from modeling employment figures
to forecasting the number of citations to academic publications. Richard is an expert in
many different areas of econometrics. Over the last four years we had many discussions
on all kinds of topics, ranging from complex Bayesian sampling schemes to the best choice
of audio equipment. Concerning econometrics, I learnt the most from the times when we
did not directly agree. I thank Richard for taking the time to discuss things until at last
I decided to accept his arguments, or (at fewer occasions) the other way around. I am
looking forward to a continued cooperation with Philip Hans and Richard in the future.
Secondly, I thank the members of the small committee, that is, Gerrit van Bruggen,
Pradeep Chintagunta and Marnik Dekimpe for evaluating this thesis. I am also grateful
to a number of anonymous referees who have given detailed comments on earlier versions
of many of the papers that form the basis of this thesis. I also thank Marnik Dekimpe
for his detailed and valuable comments on Chapter 4.
During my Ph.D. track I had the opportunity to travel around the world to visit conferences, present my work, and to meet fellow researchers. During the third year, I spent
three months at the Graduate School of Business at the University of Chicago. I would
like to thank the marketing group of the Graduate School of Business for their hospitality,
especially Pradeep Chintagunta and Peter Rossi. The financial support for these trips of
ERIM, the Econometric Institute, and the Trustfonds are gratefully acknowledged.
I thank Erjen van Nierop who was willing to share an office with me in my first year,
and Bj¨orn Vroomen who even had to put up with me for three years. I hope both of
you had a good time as well. Next, I would like to thank several generations of fellow
Ph.D.-students for sometimes serious and at other times hilarious coffee/tea sessions,
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lunches and other social activities. To name just a few I mention, Bj¨orn, David, Erjen,
Ivo, Jedid-Jah, Joost, Kevin, Klaas, Patrick, Pim, Richard, Richard, Rutger, Ward, and
Wilco.
Last, but certainly not least, I want to thank my parents who have always been a big
support and who motivate me to get the most out of the things I do.