The consequences of divorce studied by UvA and CBS

/ Author: Masja de Ree
© Hollandse Hoogte / Koen Verheijden
More and more children experience the divorce of their parents, their parents starting new relationships, and potentially the introduction of step and half siblings to the family. What are the consequences of these events for the relationships among the family members? This was the topic of an innovative survey which was conducted by University of Amsterdam (UvA), entitled “Parents and Children in the Netherlands” (OKiN). Sampling and data collection were arranged by Statistics Netherlands (CBS) and this collaboration has produced unique insights.

The divorce revolution

The number of divorces increased sharply over the 1970s and 1980s, with the emergence of more and more complex families as a result. Prof. Matthijs Kalmijn of UvA: ‘A lot of research has been done so far which focuses on the effects of parental divorce on young children in the first turbulent period after divorce. We wanted to find out how these children, who grew up during the ‘divorce revolution’ and are currently between ages 25 and 44 years, are doing now.’ Prof. Kalmijn received a grant from the European Union for his research, which was conducted in close cooperation with CBS.

Complex families

The main focus of the OKiN survey is on complex families: not only families who experienced parental divorce or separation, but also families in which one of the parents passed away or where the parent was single at the time of the child’s birth. The OKiN survey also approached families with adopted children. Kalmijn: ‘The complexity of these family situations also raises complex issues. For example: what about parental custody when multiple parents and stepparents are involved? We considered it important to study how those who grew up in complex families view such questions, and what the long-term effects of the complex family situation are on these people. Thanks to our collaboration with CBS, we obtained unique sampling material.’

Sampling frame

Prof. Ruben van Gaalen, who works both at UvA and at CBS, was responsible for the sampling frame. He specialises in register analyses and has conducted a great amount of research on the way children in the Netherlands are growing up. Van Gaalen: ‘Our registers provide a lot of information on family structures and the circumstances in which children grow up. We know where these children live, how much their parents earn, what sort of education they receive, their exposure to delinquency, etc. However, registers do not tell us anything about their family situation at home. How is co-parenting arranged? How do family members support each other? How do they perceive their own personal situation? We needed to conduct interviews in order to find that out.’


A unique aspect of this survey is that the address registrations of the parents and children were used in order to obtain a proper sample for the interviews. This resulted in large subgroups of types of families to let researchers draw meaningful conclusions. Van Gaalen: ‘Moreover, we were able to contact both the parents and the children thanks to these registers. This was also announced in the letter which notified the children and their (step)parents. In order to safeguard the privacy of respondents, the completed questionnaires were first encrypted within the highly secure CBS environment, then encoded with a so-called random identification number (RIN). This ensures none of the data contain any personally identifiable information. Only then did we combine the data on both parents and children in the OKiN survey; something which has never been done before in this type of survey. After the interviews were conducted, we again used the registers in order to supplement the data with data on e.g. income and education; this was also announced previously in the notification letter. One advantage was that we were able to prevent the questionnaires from becoming too long for the respondents.’

"The collaboration between UvA and CBS in this survey has produced information which is unique in the world."

Unique survey

The collection of survey data was done by CBS as well. Miranda de Vree was closely involved in this process. ‘The fact that both adult children and their parents were asked to participate made this survey unique, but also complex. A letter was sent out by mail to all persons involved, asking them to fill out an online questionnaire. Those who did not respond were approached by a CBS interviewer at their residential address, asking them whether they would still take part. This ultimately led to a high response rate.’ The high response rate is partly due to the combination of strategies applied by CBS. ‘For example, we approach people via the internet and in writing, as well as, face-to-face. This time we also enclosed a gift certificate with the letter which was inviting them to take part in the online survey. People are more inclided to participate when they receive such a small token of appreciation. What also worked was the topic of the survey, which both respondents and interviewers found very interesting.’

Presentation and seminar

The research into complex families is already resulting in a series of publications by researchers at UvA and CBS, as well as a number of dissertations. On 17 October, CBS is hosting a seminar by the Netherlands Demographic Society (NVD) with family complexity as the key topic. Aside from various presentations based on other surveys, Prof. Kalmijn will present the initial outcomes of the OKiN survey. The seminar will be attended by scientists, policy-makers, and family counsellors. What can they learn from this survey? Kalmijn: ‘Our survey has provided considerable insight into the diversity among step parents. This is something to consider when drafting laws and regulations. What also came forward was that parents who had lost contact with their children were experiencing great emotional difficulty, fathers in particular. This will require some counselling efforts.’ Van Gaalen draws the following conclusion: ‘The new data have produced a much more accurate picture of the effects a parental divorce has on the children and their closeness to the parents. The collaboration between UvA and CBS in this survey has produced information which is unique in the world. We’re able to demonstrate that the use of register data and interviews may lead to an efficient and accurate survey on otherwise relatively small but important for policy formation groups.’

Follow-up survey

Prof. Kalmijn would like to further extend this survey: ‘For instance, by interviewing the same respondents again in four years’ time. We are still trying to find sources of funding for this. In addition, we plan to carry out further research into adopted children and into highly complex family situations with lots of stepparents.’