After two years of digging and even legal proceedings, the editors of Nieuwsuur were given access to the ancillary activities registries of fourteen universities and seven university medical centres. In total, these contained records for only 4,200 professors, even though there are estimated to be almost 7,000 professors in the Netherlands.


A random sample shows that some of the missing professors did indeed have ancillary positions. And the data that are in the registers often turn out to be outdated, incomplete or incorrect. The registration of additional jobs and interests is mandatory to prevent scientific integrity being compromised.

At the Erasmus University, among others, many errors were found, according to Nieuwsuur. It is not entirely clear which errors are involved. The TV programme mentions former Prime Minister Jan-Peter Balkenende, who has been an unsalaried professor in Rotterdam since 2010 and of whom only one of his fifteen ancillary positions was included in the register. The ancillary positions of College President Ed Brinksma were also incomplete: his membership of the Supervisory Board of Utrecht University was not included in the register. This has since been corrected.

Smaller institutions, such as the Open University, the University of Twente and Tilburg University, keep better records of the ancillary activities of their professors than the larger ones. At the University of Groningen, more than half of the entries in the ancillary activities registry contain errors and inaccuracies, while the university’s medical centre keeps no records for its professors at all.

The latter is also the case at Utrecht University. The institution can only provide information on the ancillary activities of its professors that they themselves have listed on their public profile pages.


University association UNL, which helped Nieuwsuur collect the records, is shocked by the results of the investigation. “This can’t be allowed to continue. We have to do something about this”, says UNL chair Pieter Duisenberg. He continues:“Transparency is the cornerstone of scientific integrity. When you provide your expert opinion as an academic, everyone must be able to verify that you’re doing so independently.”

At the moment, UNL’s website still states that universities have made considerable progress in this area. By early 2021, the ancillary activities of 95 percent of all professors were supposed to be available online, up from 87 percent in 2017.

D66 education minister Robbert Dijkgraaf is troubled by the results of the investigation. “There can be no connection between science and society without 100 percent transparency. I’m going to have a conversation with the universities because I’d like to hear how they plan to remedy this.”

Former ministers

Even university administrators and former ministers – such as Jet Bussemaker and Jan Peter Balkenende – don’t always have their records in order. This is also true for former education minister Ronald Plasterk.

The latter is especially noteworthy: it was during Plasterk’s tenure that the government decided that professors’ ancillary activities should be made public. At the time, in 2008, university association UNL was against the proposal, while the Royal Netherlands Academy of Arts and Sciences was in favour.

Since then, there have been regular news stories about the incomplete registration of professors’ ancillary activities, invariably followed by public outcry. In 2009, HOP looked into how things were going. The conclusion: not well. Two years later, in 2011, the then government once again stressed that ancillary activities should in principle be a matter of public record. De Groene Amsterdammer wrote about this in 2014.

In 2013, Dijkgraaf’s predecessor Jet Bussemaker refused to set up a national registry, and in 2015 she downplayed the problem: some things were just private, meaning they didn’t need to be registered.

There have been several signs in recent years that ancillary activities can compromise scientific integrity. Recently, de Volkskrant and Folia published articles about the conflicts of interest of professors of tax law and tax economics. An earlier story by Nieuwsuur on the Groningen ‘passport professor’ Dimitry Kochenov resulted in this follow-up investigation.

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