This text is part of a series of essays dedicated to Open Data Day, organised by Open State Foundation and Open Nederland. The Open Knowledge Foundation is proud to be a publishing partner.
Companies build new services, researchers discover patterns and citizens solve local problems faster. Those who share, multiply. Think of it like a miracle seed: sometimes nothing happens, sometimes a single sprout leads to a forest of innovation.
The report, “De Baten van Transparantie”, conducted by Open State Foundation and Instituut Maatschappelijke Innovatie, estimates that open data in the Netherlands generates around €3.5 billion annually. That is real societal value; money saved, innovations launched, policies improved and citizens empowered. Yet, despite these numbers, open data often remains a secondary concern in politics.
The rational investor
Although there are many examples of how open data reuse generates societal value, this potential is sometimes forgotten in political debates on open governance. In the Netherlands, there is currently a tendency toward more closed governance, as public administrators and politicians argue that transparency is too costly and burdensome to implement in public policy.
Investments typically have a price tag, but they also generate benefits. Looking at it from an economics perspective (to stay in line with the current political debate focussing on the costs), a “rational” investor always outweighs the total costs against the expected returns.
Discussing open data solely in terms of costs, without considering the returns, seems odd. One of the reasons behind this might be that the benefi ts of open data are often diffi cult to quantify, because although governments collect and publish the data, the resulting value materializes throughout society.
The aim of our research was to assess and quantify the benefits of transparency. We hope this brings more balance to the debate and puts things into perspective. Based on an extensive literature review and juridical analyses of the Dutch context, we categorized the benefi ts of open data into four groups: innovation, government effi ciency, accountability, and participation.
Example 1: regional climate monitor
The first example demonstrates how open data improves government efficiency. Surprisingly, governments are often their own largest re-users of the data they publish. Yet, although citizens tend to perceive “the government” as a single entity, data rarely flows freely between departments. Without open data, double data collection is common; multiple departments collect the same information, wasting time and resources. The “once-only principle” ensure that data collected once can be reused wherever it is needed.
The Dutch Regional Climate Monitor illustrates this perfectly. This dashboard offers open data on emissions, renewable energy and energy consumption, available across all government levels and sectors. Policymakers no longer need to collect and process the data themselves; instead, they can rely on a uniform, up-to-date dataset.
The benefits are tangible: administrative burdens are reduced and interdepartmental coordination improves. Moreover, the dashboard allows municipalities to compare performance, fostering mutual learning. This way, municipalities can identify best practices, improve their policies, and save on consultancy costs.
Example 2: Zonopjebakkes
When data is opened to the public to re-use, it can spark unexpected social innovation. In the Netherlands, vitamin D is scarce in the Netherlands, so people cherish every sunbeam. By combining open datasets such as 3DBAG (building data), BGT (Topography data), AHN5 (elevation data) and the NWB (national roads data), Social Technology Lab created Zonopjebakkes, which means “sun on your face”.
This free app shows which terraces receive sunlight at every moment of the day. Users can add their favorite spots, creating a community-driven map of sunlit areas. What seems like a simple idea, tracking sunlight, has broader implications: encouraging outdoor activity, enhancing well-being and even supporting local businesses that host sun-seekers on terraces.
Zonopjebakkes exemplifies how open data fuels grassroots innovation. It shows that benefi ts of transparency extend beyond economic gains; they touch everyday life in ways that are often surprising.
Example 3: livestock data
Sometimes, data stays closed; not because of financial costs, but due to political ones. A recent Dutch case illustrates what’s at stake. Former Agriculture Minister Femke Wiersma blocked the publication of livestock data that, under the Aarhus Convention, should be published. Journalists from Follow the Money, NRC and Omroep Gelderland took her to court, and the law ultimately compelled release.
By analysing the dataset, the journalists found serious inefficiencies in the government’s voluntary buy-out scheme for high-emitting farms: €1.8 billion was spent to remove 723 farms as to reduce total emissions produced, while the same nitrogen reduction could have been achieved for roughly €325 million by targeting the 133 largest polluters. The data also exposed public health risks: municipalities were allowing tens of thousands of houses to be built near goat farms, which are known to carry increased risk of pneumonia.
This case demonstrates that open data is crucial for accountability, public scrutiny and protecting the public interest. Even when political costs make transparency uncomfortable, the societal benefi ts far outweigh the perceived risks.
Making up the balance
Getting open data higher on the political agenda is essential. Open State Foundation, together with the Open Knowledge Foundation, celebrates the societal benefi ts of open data during Open Data Days. The examples highlighted – the Regional Climate Monitor, Zonopjebakkes, and livestock data – illustrate the diverse ways that open data generates tangible value.
It saves money, improves effi ciency, stimulates innovation, and enables journalists to execute their role as public watchdogs and enforce accountability. According to our report De Baten van Transparantie, these benefi ts of open data result in an estimated total annual value in the Netherlands of around €3.5 billion. Preventing duplicate administrative work alone is estimated to save €50 million a year.
We can conclude that open data is a driver of public value. So open up data, let photosynthesis do its work, and before you know it a whole chain of invention will sprout. Whether through government dashboards, community apps, or investigative journalism, open data proves that sharing knowledge is not just a principle, it is a practice that creates measurable, tangible value for society.
Over the coming days, we are excited to share a series of essays from different initiatives that highlight this societal impact of open data.
About Open Data Day
Open Data Day (ODD) is an annual celebration of open data all over the world. Groups from many countries create local events on the day where they will use open data in their communities. ODD is led by the Open Knowledge Foundation (OKFN) and the Open Knowledge Network.
As a way to increase the representation of different cultures, we offer the opportunity for organisations to host an Open Data Day event on the best date over one week. In 2026, a total of 131 events happened all over the world between 7–13 March. All outputs are open for everyone to use and re-use.
Join the community:
- For peer-to-peer advice and collaboration: Open Data Day Forum
- For official news & announcements: Open Data Day Google Group
- For consultations with the OKFN team: opendataday@okfn.org
