The GGS targets an average of 10,000 respondents per country and collects data on the whole life course by interviewing respondents aged 18-79. It enables analysis of numerical minorities, uncommon events, and multiple generations.
The GGS is designed as a large-scale survey, aiming to cover approximately 10,000 individuals aged 18–79 or 7,000 individuals aged 18–59 in countries where a separate ageing survey is available. This large sample size is crucial for researchers to study population subgroups—such as ethnic minorities or same-sex couples—that are underrepresented in smaller surveys. It also enables the GGS to capture rare demographic events and ensures that a sufficient number of key events (e.g., births, marriages, divorces) occur between waves to support robust longitudinal analysis.
| GGS Round I, Wave 1 | GGS Round II, Wave 1 | ||||
|---|---|---|---|---|---|
| Completed interviews | Age range | Completed interviews | Age range | ||
| Argentina (Buenos Aires) | - | - | 2,294 | 18-79 | |
| Australia | 12,759 | 18-79 | - | - | |
| Austria | 5,000 | 18-45 | 6,781 | 18-59 | |
| Belarus | - | - | 9,562 | 18-79 | |
| Belgium | 7,163 | 18-79 | - | - | |
| Bulgaria | 12,858 | 18-79 | - | - | |
| Croatia | - | - | 6,894 | 18-54 | |
| Czech Republic | 10,006 | 18-79 | 5,463 | 18-69 | |
| Denmark | - | - | 4,986 | 18-49 | |
| Estonia | 7,855 | 21-80 | 9,257 | 18-59 | |
| Finland | - | - | 2,954 | 18-54 | |
| France | 10,079 | 18-79 | 13,316 | 18-79 | |
| Georgia | 10,000 | 18-74 | - | - | |
| Germany | 10,017 | 18-79 | 184 | 18-59 | |
| Germany (Turkish sub-sample) | 4,045 | 18-79 | - | - | |
| Hong Kong | - | - | - | 18-59 | |
| Hong Kong (SAR) | - | - | 4,236 | 18-59 | |
| Hungary | 13,540 | 21-78 | Pending | 18-59 | |
| Iceland | - | - | In prep. | 18-79 | |
| Italy | 9,570 | 18-79 | Pending | 18-59 | |
| Japan | 9,074 | 18-69 | - | - | |
| Kazakhstan | - | - | 14,039 | 18-79 | |
| Latvia | - | - | In prep. | 18-59 | |
| Lithuania | 10,036 | 18-79 | In prep. | 18-54 | |
| Moldova | - | - | 9,894 | 15-79 | |
| Netherlands | 8,161 | 18-79 | 7,355 | 18-59 | |
| Norway | 15,114 | 18-79 | 4,571 | 18-54 | |
| Poland | 19,987 | 18-79 | In prep. | 18-79 | |
| Romania | 11,986 | 18-79 | - | - | |
| Russian Federation | 11,261 | 18-79 | - | - | |
| South Korea | - | - | Pending | 18-59 | |
| Sweden | 9,688 | 18-79 | 8,013 | 18-59 | |
| Switzerland | - | - | In prep. | 18-79 | |
| Taiwan | - | - | 7,594** | 18-79 | |
| United Kingdom | - | - | 7,214 | 18-59 | |
| Uruguay | - | - | 7,101 | 18-79 | |
Source: Information is taken from the GGS Study Documentation for each country available on the GGP Colectica portal (https://ggp.colectica.org/).
For Australia, data are drawn from the HILDA User Manual (Release 22). GGS-I Wave 1 corresponds to HILDA Wave 5. For Japan, the source is the Country Progress Report on Japanese GGP submitted to UNECE.
Australia, Italy, Japan, Netherlands - For these countries, data have been post-harmonized to align with the GGS framework.
**Estimates based on the latest data export; data collection is still ongoing.
