Frequently Asked Questions

You can complete the registration form here:

If you register, you can be invited to (online) GrEELab experiments. You can then decide whether you want to participate in that experiment. Each invitation will mention how much money you can earn in that experiment, and where (e.g. online) and when the experiment will take place.

GrEELab stands for: Groningen Experimental Economics Laboratory. As the name suggests, its main purpose is to host economic experiments. It is operated by researchers from the Department of Economics, Econometrics and Finance at the University of Groningen.

Students can earn money by participating in GrEELab experiments. Participation also benefits science, because it enables researchers to conduct studies (without participants, we cannot run experiments).

During a typical GrEELab experiment you sit in front of a computer and conduct some tasks or make a choice between specific options. Importantly, you get paid for the tasks that you do or the choices that you make. The experimental instructions will always explain what you need to do and how the magnitude of your earnings depend on the things that you do. No prior knowledge is required to participate.

Every experiment is different, but on average an experiment will last for 1 or 2 hours. The invitation for the experiment will always indicate how long the experiment will take.

You will always get paid if you complete an experiment. The exact amount depends on the specifics of the experiment. For example, it can depend on performance in a task, on the choices of participants, or on other elements such as a lottery. The average payment is typically 9-10 euros per hour. This is an average, which means that your earnings could be considerably more, or somewhat less (there is typically a minimum amount, which will be mentioned in the invitation). 

Each invitation will mention how much money participants can expect to earn in that experiment, and you can then decide whether you want to enroll for that particular experiment. During the experiment the instructions will explain how your earnings are determined (e.g. how much you get for a certain performance in a task). Your payment will always be in line with the instructions.

Payments will happen via FedRbp, which is the official automated payment system of the university. You need to register there to be able to receive payments. Note that FEDRbp requires an IBAN from the SEPA region. This includes all EU countries with a few additions.

To read about the FedRbp go here: You can set the language of the FedRbp page on the top right corner of that page.

To register yourself directly go here: 

Note: GrEELab and the FedRbp system are separate from each other and we cannot register you in FedRbp, you need to do that yourself.

First of all, you need to complete your registration by filling in the registration form.

After you are registered, you may receive invitations for experiments. If you are invited to an experiment, you will see which time-slots are available for that experiment and you can enroll yourself for the one that fits you most.

Our lab is on the ground floor of the Duisenberg building, in room 5412.0014, just beside the entrance that is facing the Kapteijnborg.

GrEELab obliges its researchers to keep their promises, so the experimenters have to make sure that everything that they say to participants is true. This holds not only for the magnitude of the payments, but also more generally.

For example, if the experimental instructions state that you are paired with another participant for a certain task then the experimenter has to make sure that this is indeed the case. Another example is that if the instructions describe a lottery then the experimenter has to make sure that the lottery is conducted with the exact probabilities that were told you in the instructions.

Yes, your participation in an experiment is voluntary and you can leave any time. However, if you leave without completing the experiment you will not be paid for your participation.

One reason could be that you did not fill in the Registration Form and therefore your registration is not complete yet.

Another reason could be that only a subset of people were invited to participate in that experiment. This is not a mistake, the list of invitees can vary from experiment to experiment. 

If you are not invited to a specific experiment, you can not participate in that experiment. You may, however, be invited for another experiment. 

You can deregister from the participant registry by sending an email to in which you explain that you want to do this. In this email you can also indicate whether you want to delete the information that you provided via the Registration Form.

If your question is not answered above, you can send an email to