Structure
The plan is to regularly survey the same people over a period of 12 years, based on a Germany-wide residents' registration office sample of the adult population living in Germany, regardless of their nationality. The initial sample in fall 2024 had a size of 80,000 people.
Mode
Data collection will take place in multiple panel waves using self-administered online and paper-based surveys. The focus will be on recurring panel modules to enable longitudinal analyses.
Contacting
After postal recruitment, two different contact methods are used from the first short survey onwards: Depending on whether the respondents have provided an e-mail address, they are invited either by post or by e-mail. The incentive also varies according to the type of contact. However, participation in the study is predominantly online.
Add-ons
Experimental designs such as factorial survey experiments and questionnaire splits will also be integrated. Data users also have the opportunity to ask their own questions in open modules. Both panel designs and experiments are also possible here. Researchers can currently submit their own modules to us, further information can be found here.
GLEN+ Studies are add-on studies to be implemented after the initial setup of the Germany-wide panel. Additional data collection is planned in cooperation with external administrative, political, or scientific partners. For instance, regarding regional in-depth analyses of local policies or dynamics, GLEN+ studies can use additional regional samples that may be combined with randomized controlled trials, for example in the form of information-treatment or nudging-default experiments, or with added local geo-referenced data records on environmental topics. These studies may use (parts of) the same core questionnaire as the main GLEN study and hence provide potential for comparisons between national and regionally constrained levels.
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