Estimates of unlicensed online gambling in the Nordic countries vary widely and are often based on non-transparent data sources. This is shown by a new scoping review published in PLOS ONE. Led by researchers from, among others, Karolinska Institutet, the study reviews 32 reports and finds that figures describing the "black market" are frequently used as political arguments, despite unclear underlying methodologies.
Unregulated gambling refers to online gambling offered by operators without a national licence. These operators are often based in grey or black markets where consumer protection, age verification, and regulatory oversight are inadequate or entirely absent. Keeping gambling within the regulated market is therefore crucial to ensuring stronger player protection and reducing risks such as crime, money laundering, and exposure to particularly harmful gambling products.
Despite unlicensed online gambling often being portrayed as a growing problem, the researchers show that current methods used to estimate the size of this market are unreliable.
"Current estimates are too uncertain to be used as a basis for political decision-making. If we do not know how the figures are produced, they can be misused to influence policy, even though they rest on weak foundations," says Håkan Wall , researcher at the Department of Clinical Neuroscience and the Centre for Psychiatry Research , Karolinska Institutet and Region Stockholm, and one of the study's authors.
Researchers' warnings
A declining channelisation rate is frequently highlighted by the gambling industry as an argument against stricter regulation, even though the evidence may be methodologically weak. The researchers warn that:
- exaggerated figures on unlicensed gambling may undermine regulation and consumer protection
- shortcomings in measurement make it difficult to assess the effects of legislative changes, such as licensing systems and advertising restrictions
- the unregulated gambling market largely represents an extension of problems that already exist within the regulated market, particularly in online casino and sports betting
Need for more open and robust methods
One conclusion of the study is that more reliable measures require greater methodological transparency and the combination of multiple data sources. The researchers point out that a broader set of independent, comparable indicators could reduce the risk of uncertain estimates being used as arguments in politically charged debates, thereby strengthening efforts in harm prevention and online consumer protection. They also argue that the Nordic countries need expanded capacity to address unlicensed gambling, allowing resources to be focused on reducing harm within the regulated market.
The study is a collaboration between researchers at the University of Helsinki, Aalborg University, the Finnish Institute for Health and Welfare, Karolinska Institutet, and Region Stockholm. The authors report no conflicts of interest. Håkan Wall receives funding from Forte, the Swedish Research Council for Health, Working Life and Welfare.
Publication
"Uncertainties in measuring offshore gambling, a scoping review of Nordic approaches" ,
Virve Marionneau, Søren Kristiansen, Tomi Roukka, Håkan Wall, PLOS ONE, 23 January 2026,
doi: 10.1371/journal.pone.0340727.
