Frequently asked questions

VAL is a scientific study led by researchers at the University of Iceland. It is part of an international research project that aims to improve our understanding of human behavior and decision making. Such knowledge can help improve policy, services and solutions in many areas of society.

You can participate if you are 18 to 66 years old, have an electronic ID (rafræn skilríki) and normally live or stay in the capital area. It does not matter where your legal domicile is registered.

The study is intended for people who live in the capital area. However, it is not tied to your registered legal domicile. You can participate if you live in the area or normally stay there, for a longer or shorter period, even if your legal domicile is registered elsewhere.

The study is carried out in collaboration with providers that sell passes giving access to services, and such collaboration is necessary in order to answer certain research questions. All of the services used for this purpose are in the capital area. These are the Reykjavik swimming pools, Strætó bus services, the Reykjavik Culture Card and the Katla Fitness gyms. Participation is therefore limited to the capital area, so that participants can genuinely make use of the passes that may be offered.

In the study, some participants can buy certain services at a reduced price. This includes services that are free of charge for people aged 67 and older, or available to them at a heavily reduced price. The discount arrangement on which the study is based therefore does not apply to that age group.

No. Each individual can only participate once in this version of the study. There may, however, be opportunities to take part in follow-up studies later.

Some participants receive direct cash payments of up to ISK 15,000. Such payments are deposited into the participant’s bank account. Participants may also be offered a pass at a discount: a bus pass from Strætó, a gym pass from Katla Fitness, the Reykjavik Culture Card or a swimming-pool pass from the City of Reykjavik. Participants can also receive personal feedback consisting of information about their own behavior compared with others. Such feedback is sent later, and only if the participant has indicated that they want it.

No. Participants do not all answer the same questions and may follow different paths through the study. This is not an error; it is part of the study design. Two people taking part at the same time may therefore have different experiences.

All participants receive clear information and instructions about each part of the study that is presented to them.

No. If you are offered the opportunity to purchase a pass, you will first be asked which service you would most like to receive an offer for, from among the services to which you do not already subscribe. You will receive one opportunity to purchase a pass for that service.

The price of the pass is then drawn at random and may therefore differ between participants. If the price drawn is higher than the maximum price you stated, no purchase takes place and you will not be offered another pass later in this participation.

Further information about how the price is determined is provided under “How is the price of the pass determined?”

If you receive a payment as part of your participation in the study, it will be deposited into the bank account you provide in the study interface. The amount of the payment depends on your choices in the study and on random selection.

You first state the highest price you are willing to pay for the pass. The spinning wheel then draws a price at random, ranging from zero up to the market price of the pass. All prices in that range are equally likely, regardless of which maximum price you chose.

If the price drawn is equal to or lower than the maximum price you stated, the purchase is made and you pay the price drawn, not the maximum you stated. If the price drawn is higher, no purchase takes place.

It is therefore always in your interest to state the maximum amount you are truly willing to pay.

If you state a maximum price higher than you are genuinely willing to pay, you risk ending up buying the pass at a price higher than you actually want to pay.

If you state a maximum price lower than the price you would genuinely have been willing to pay, you may miss out on buying the pass at a price you would gladly have paid.

Payment for a pass is made by payment card in the study interface. If a purchase takes place, the pass will be created with the relevant service provider (Strætó, Katla Fitness or City of Reykjavik). The information necessary to create the pass is then sent to the service provider responsible for issuing or activating it. You will receive all the information you need about how the pass is activated once the purchase has gone through.

Yes. To complete your participation you need to enter a payment card number in a secure interface, because participation involves the possible purchase of a pass at a discounted price. This is a condition of participation, not a consequence of buying a pass.

You can always choose not to provide a payment card and to end your participation instead. Payment card information is handled by the payment processor Verifone on behalf of Landsbankinn, which complies with international PCI DSS security standards, and it is deleted once payments are complete.

Yes, if you choose to. As you are completing your participation you can indicate whether you want personal feedback showing the characteristics of your decision making compared with other participants. This is optional. You can accept the feedback or decline it; the choice has no effect on anything else in the study.

The feedback is not sent as soon as you finish participating, but after the study itself has ended. It will be sent to the email address you provide. You need to have completed your participation to be eligible for feedback.

The risk associated with participation is considered negligible. The study does, however, involve a spinning wheel and random selection, which may resemble gambling. People with a gambling addiction should bear this in mind before deciding to participate.

The SÁÁ gambling problem team provides assistance with gambling problems: spilavandi@saa.is or telephone +354 530 7600.

Before participation begins you receive information about the study and about how your data will be stored and used. We then ask you to agree to the terms of the study on the basis of that information (informed consent). Participation in the study is subject to the conditions set out in the informed consent.

You can read the consent in full here.

You have 24 hours to complete your participation. The countdown starts when you log in with your electronic ID.

Within those 24 hours you can close the interface at any time and log in again with your electronic ID to continue where you left off. After that time, access closes and further participation is not possible.

Being eligible for a cash payment requires that you complete the whole study within those 24 hours. If you buy a pass in the study, it is yours as soon as the purchase has gone through, regardless of whether you finish the study.

The informed consent is presented to you after you log in, when the countdown has already started. You can, however, read the informed consent here before you begin, without starting the clock.

It is standard practice in research on behavior and decision making not to disclose the precise research questions in advance. The reason is that a participant who knows what is being measured is likely to change their behavior, usually without meaning to. The study may then measure reactions to the question itself rather than the behavior it was meant to examine, which reduces the value of the results.

This is not deception. Nothing you are told in the study is untrue. You receive full information about what participation involves, how the data are stored and used, what you may receive and what rights you have, before you agree to participate. The only thing not stated in advance is which particular questions the results are meant to answer.

The results of the study will be published openly once they are available.

No. Your answers are stored under an encrypted identifier and analysis uses data from a research database that contains no directly identifiable information such as names or personal ID numbers. The encryption key is kept separately from the data by the Division of Information Technology at the University of Iceland. Researchers do not have access to the key, and no personally identifiable information appears in published results.

The encryption key is, however, used in a limited number of cases that are necessary in order to carry out the study: to link answers with usage data from the organisations that provide the services (Strætó, Katla Fitness and City of Reykjavik) and other data sources, to activate a pass, to pay participants and report payments to the tax authorities, and to send you your own feedback if you ask for it. In each case only the information needed for that particular task is used.

To promote transparency and reproducibility, data from the study, under encrypted identifiers, will be made available through controlled access. Researchers at recognized research institutions anywhere in the world can apply for access to them.

This means that the data may be transferred outside the European Economic Area. Such transfers are carried out in accordance with Chapter V of the European Union’s data protection regulation (GDPR), with appropriate safeguards. No personally identifiable information is shared.

Participation is always voluntary and you never have to give a reason. Two situations can apply.

Stopping while the study is under way. You can close the interface at any time and simply not continue. Being eligible for a cash payment does, however, require that you complete your participation in the study within 24 hours of first logging in with your electronic ID. A pass you have already bought is yours regardless of whether you finish.

Withdrawing your consent later. You can also contact us and ask that your data not be used further, that your answers not be linked to other data sources in the future, or that you not be invited to take part in other studies. Send an email to rannsoknin.val@hi.is or call +354 525 4545 (the Social Science Research Institute, University of Iceland).

Some things cannot be undone, however. Purchases that have been completed are not reversed, and payments that have already been made are not recalled. The same applies to processing of data that has already taken place, such as analyses that have already been carried out and results that have already been published. Withdrawing your consent stops further use of your data in the study, but it does not undo what has already been done.

Stopping after a purchase of a pass has gone through does not affect the purchase; the pass is yours. You will not, however, be eligible for cash payments. Only participants who complete the study are eligible for payments. The same applies to personal feedback based on information from the study.

The principal investigator is Tinna Laufey Ásgeirsdóttir, professor at the University of Iceland. The following researchers are also involved in the project:

• Matthias Wibral, associate professor, Maastricht University, the Netherlands
• Arno Riedl, professor, Maastricht University, the Netherlands
• Matthias Sutter, professor, Max Planck Institute for Behavioral Economics, Germany
• Michał Krawczyk, professor, University of Warsaw, Poland
• Hjördís Harðardóttir, project manager, University of Iceland
• Helgi Guðmundsson, specialist, Social Science Research Institute, University of Iceland
• Cass Sunstein, professor, Harvard University, United States
• Hulda Þórisdóttir, professor, University of Iceland
• Guðberg Konráð Jónsson, director, Social Science Research Institute, University of Iceland

Yes. The research protocol was submitted to the ethics committee of Maastricht University, which on 25 May 2026 raised no ethical objections to how the study is conducted. The study is carried out in international collaboration and part of the research team works there. The study does not require approval from the National Bioethics Committee under Act No. 44/2014 on Scientific Research in the Health Sector, nor approval from the Data Protection Authority under Act No. 90/2018 on Data Protection and the Processing of Personal Data, since the general processing of research data is based on the informed consent of participants.

Questions about the study and participation in it may be directed to the research team at rannsoknin.val@hi.is or to the Social Science Research Institute at the University of Iceland by calling +354 525 4545. The Social Science Research Institute carries out the data collection.

The data controller for the processing of personal data is the University of Iceland. Questions about data protection can be directed to the university’s Data Protection Officer, Magnús Jökull Sigurjónsson, mjs@hi.is, telephone +354 525 4052.