In May 2017 I filed a request for the release of a report at the city of The Hague. It was a report of a research into the real number of visitors to some major events in the Hague. This request was denied, however, on grounds that the results contained sensitive commercial information, provided by the organisers. This in itself is only partly true: the information is sensitive no doubt, but it was not provided by the organisers of the event. It is sensitive because the organisors don’t want it published.

The problem is the untrustworthy and exaggerated number of visitors communicated by event organisers, in The Hague and other cities. This problem is not new, it’s been known for decades here in the Netherlands. In 2005 I was confronted with this problem when I was asked to calculate the economic impact of sports events in the city of Rotterdam. What struck me was that especially the free events in the public space, like the Rotterdam Marathon and the nationale championships cycle racing reported unrealistically high numbers of visitors. This would lead to an even unrealistically high economic impact.

Prisoner’s dilemma

These figures were critized already at that time. Wim Pijbes (later director of the Rijksmuseum) and Leon Ramakers wrote an opinion article in a Dutch newspaper ‘The event industry bluffs with too impressive figures for number of visitors’. They showed that there was symply not even enough capacity in the city to host the visitors which were reported.

The problem is a typical prisoner’s dilemma: if one organisor decides to communicate the real, i.e. lower visitors, his event is punished by a fall in the ranking of most popular events. And the differences are big. The real number might be half or even a quarter of those which are now told tot the press.

In 2006 a collegue, Lex Kruijver and I initiated a solution. If all parties concerned would agree to communicate real figures, the correction would apply to all parties – of course for some larger than for others. This would be secured by a convenant, signed by the most important stakeholders.

In April 2007 this agreement was signed by five large Dutch cities, advertisers and organizers. But despite this success, (too) little has changed the last 10 years. Still cities and organisors of events are in a mutual hostage relationship with their inflated figures.


However, two recent developments may help to revive the agreement. The first development is the obligation of sports events, subsidized by the Dutch ministry of sports, to use the so-called WESP guidelines. (WESP is a community of experts which share knowledge and formulate best practises, laid down in guidelines). These guidelines prescibe a.o. that the number of visitors should be measured, not just reproduced from what the organizers communicate. This means that for large sports events, which are evaluated according to the guidelines, the numbers are reliable. But not all events are evaluated according to these guidelines.

The second development is the technical innovations which make it easier to count visitors. The availability of mobile phone data makes it possible to make more accurate estimates of large crowds in public spaces. Cities sometimes purchase these estimates but there is a catch.

Although some cities have these more accurate numbers, they don’t publish them. The obvious reason is that they don’t want to jeopardize their relationship with ‘their’ events and organizers. An example is the city of The Hague. In 2016 they have commissioned a study into the number of visitors of 16 hallmark events. However, the city doesn’t dare to publish the results. This is the report which I have referred to above.

Mutual hostage relationship

A some point in time, this mutual hostage relationship should be broken, for the benefit of all. If one city breaks this bond, the others will probably follow and the whole event sector will profit.
My appeal to the decision will be handled probably in February 2018.
The documents (in Dutch) can be found at