The survey experiment data was collected by the polling company YouGov Denmark, who have access to large panels of respondents in each of the two countries. 1000 respondents in each country who identified as Christian, Protestant or Catholic when asked what religion, if any, they belong to in a screening question were entered into the full questionnaire. YouGov collects information on the gender, age, geographic region and education of their panel respondents, and the sample is representative, and weighted according to these characteristics. The questionnaire was designed in English and translated and back translated to Dutch and Danish respectively to ensure the similarity of meaning in the different languages. The survey experiment was conducted as a 2x2x2 design, with Country, Prime and Frame being the distinguishing variables. Prime: In each country participants were divided into two equally sized groups. Each group was primed with a brief statement about either the Uncontrollability of their financial future, or their Control over their financial future. In each condition they were also asked to provide three reasons (in their own words) why they were either in control or not in control of their financial future. Frame: The participants were then given 10 statements about their religiosity to answer on a scale from (0) "Do not agree at all" to (10) "Completely agree". Each participant was presented with one of two different frames:The collective identity frame includes statements such as: "I consider myself a Christian because: I am Danish / Dutch, I celebrate Christmas, I was Baptised, My mother and/or father are Christian". The personal identity frame includes statements such as: "I consider myself a Christian because I have a personal relationship with God, I believe in an afterlife, I am a spiritual person". A number of sociological and psychological studies have shown that situations of insecurity and threat could increase religious in-group identification. The proposed research project investigates whether between-country differences in Christian identity, would be strengthened by priming participants with salience of threat to the national economy. A survey experiment will be conducted on a large representative sample of self-defined Christians from the Netherlands and Denmark, two countries with marked difference in the relationship between religious and national identity. Our hypothesis is that these differences would be heightened in a situation of threat salience. Specifically, we predict that people primed with control threat will describe their religion more in terms of collective identity in Denmark, and personal identity in the Netherlands.

The method of data collection is Online survey. The respondents were members of the YouGov Panel in Denmark, or the partner organisation's panel in the Netherlands. The target group of the survey was Christians 18-74 years old, national representative on gender, age, geography and education. Invitations were sent out via email to people who meet these conditions in The YouGov Panel. The survey was selected to a sampling frame that ensured correct population proportions according to the target group. In Denmark, a total of 2113 interviews were conducted, of which 1006 are within the target group. In the Netherlands, A total of 1317 interviews were conducted, of which 1008 are within the target group.