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 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

Looking at Luxembourgish nationals through ancestry from the three countries as a whole, our statistical level of confidence is 97% with a margin of error of 5% (computed with the Raosoft sample size calculator).

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):

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).