Our Research

Research Methodology & Data

Written by: Daniel Atz — Founder, LuxCitizenship

Since 2018, LuxCitizenship has published the only recurring demographic research on Luxembourg’s dual citizens through ancestry. This page documents how the research is produced, and makes our compiled datasets available for download and citation.

The 2024 edition, The LuxCitizenship Study 2024, is published as both a report and a 113-page book (Connaissance Solutions LLC, New York, November 2024) and is held by the Centre de Documentation sur les Migrations Humaines in Dudelange.

The Survey

The current edition of the Luxembourg Dual Citizen Study is based on a survey of 1,174 confirmed Luxembourgish dual nationals through ancestry born in the United States, Brazil, and Argentina: 416 American-Luxembourgers (35%), 634 Brazilian-Luxembourgers (54%), and 124 Argentine-Luxembourgers (11%). The survey gathers demographic information, perceptions and use of Luxembourgish nationality, and respondents’ relationship with Luxembourg and the European Union.

We conducted the study through an online survey on luxcitizenship.com, promoted through our and partner organizations’ websites, social media, and email lists, as well as public social media groups for Luxembourgish dual nationals. The survey was written in the native language of each of the three countries by native speakers. Our partner organizations: the Luxembourg Brotherhood of America, the Association of Luxembourgish Citizens in Brazil, and the Argentine Luxembourg Association.

Verification

To participate, respondents had to be confirmed dual nationals of Luxembourg through ancestry. We only accepted responses where information about the respondent’s Luxembourgish ancestor was provided and where we could verify the ancestor in Luxembourgish civil records. Approximately 100 additional responses were rejected on this basis, and we contacted all respondents who did not provide ancestor information to request and verify it.

Each survey consisted of a maximum of 30 questions — a mix of yes/no, multiple-choice, and fill-in-the-blank formats. Logical dependencies meant many respondents encountered 20 questions or fewer.

Confidence Levels

The survey drew 1,174 responses from confirmed dual nationals. Respondents volunteered rather than being randomly selected, so the sample-size calculation (97% confidence, 5% margin, via the Raosoft sample size calculator) describes the size of the sample relative to the population, not the absence of self-selection bias.

Government Data

Alongside the surveys, we maintain a continuous compilation of Luxembourg government data: the Registre National des Personnes Physiques (RNPP) series on Luxembourg nationals abroad, Luxembourg Ministry of Justice nationality statistics, STATEC, and the Luxembourg National Archives for ancestor verification. Our analysis is published at Luxembourg Public Data Research and updated quarterly.

Download Our Data

We publish our compiled datasets for journalists, researchers, and the public under a CC BY 4.0 license (free to reuse with attribution):

Luxembourg Nationals Abroad — Quarterly, 2018–2026 (CSV) — the RNPP series for the United States, Brazil, Argentina, France, Belgium, and Germany, 30 April 2018 through 30 June 2026.
Luxembourg Nationals Abroad — Annual, 2018–2025 (CSV) — year-end totals with annual change and growth rates.
Article 89 Recoveries by Nationality — Provisional (CSV) — recoveries and Article 23 options as of 31 December 2025. Note: the Article 89 window closed on 31 December 2025, but declarations lodged before the deadline were still being processed; final figures are expected in the Ministry of Justice release of January 2027, and this dataset will be updated at that time.
The LuxCitizenship Study 2024 (PDF) — the complete report.

How to Cite

The study:

Atz, Daniel, with Lauren Lowell. The Luxembourg Dual Citizen Study (5th edition). LuxCitizenship Research, 2024. https://www.luxcitizenship.com/research/

The data compilation:

Atz, Daniel. “Luxembourg Nationals Abroad, 2018–2026 (RNPP compilation).” LuxCitizenship Research, 2026. Underlying data: data.public.lu (RNPP); Luxembourg Ministry of Justice.

For press inquiries about this research, contact info@luxcitizenship.com. More about the author at danielatz.com.

Research team: Daniel Atz (lead), Lauren Lowell (research & design), Verônica Bochi (Brazil research).