23,034 rated or chosen profiles from 3,839 respondents, in up to 3 tasks of 2 profiles varying on 6 attributes.

About this table

Description	Adults in France, Germany, Italy, the Netherlands and Spain (IPSOS opt-in panels, November 2022; n=3,839) chose between two hypothetical European security pacts (goal, financing, governance, opt-outs, joint purchases, size) and rated each on a 5-point scale; 3 pairs each, military-framing arm.
Reference	Nicoli, F., Burgoon, B., & van der Duin, D. (2025). Citizen support for a European Defense Union: An international conjoint experiment on security cooperation in Europe. International Studies Quarterly, 69(3), sqaf044.
DOI	10.1093/isq/sqaf044
Licence	CC0 1.0
Source data	https://doi.org/10.7910/DVN/HTAPIS

Notes

Conjoint table (irw_conjoint). choice = which of the two security packages the respondent preferred (forced choice; wording paraphrased in the article); rating = each package on 1 strongly against - 5 strongly in favor. Attribute text is the English master (Table 1), not the national-language text shown; attribute order randomized per respondent but not recorded. Five countries pooled (cov_country, cov_survey_weight). Energy-framing arm of the same survey not included. 3,839 respondents vs 3,750 in the article; 2,893 pass the attention check.

These notes describe the source data, which the IRW reproduces as released. All notes are listed on the Data Notes page.

Size and shape

Respondents	3,839
Rows (one per respondent, task and profile)	23,034
Tasks per respondent (most)	3
Profiles per task	2
Attributes	6
Tasks with no profile chosen	0

Design

Topic	foreign policy security
A profile represents	policy
Country	FR, DE, IT, NL, ES
Language shown	unknown
Language of stored levels	en
Task order	recorded in the deposit
Profile position	recorded in the deposit

Outcomes:

choice	Which of the two packages on the screen do you prefer? (paraphrase) [choice, forced]
rating	How much are you in favor of or against this package? (paraphrase) [rating, 1 (strongly against) to 5 (strongly in favor)]

Columns

attr_financingattr_governanceattr_joint_purchasesattr_opt_outsattr_programmeattr_sizechoicecov_agecov_attention_passcov_countrycov_education3cov_survey_weightidprofileratingtask

The layout (one row per respondent, task and profile; choice/rating outcomes; attr_ columns holding each attribute level as displayed) is defined in the IRW conjoint standard. What the outcomes asked is under Design above.

Get the data

Download CSVno account needed Browse on Redivisexplore and query Croissant metadataHugging Face, Kaggle, OpenML

Or load it directly in R or Python (both need a free Redivis account; the first call opens a browser to sign in):

# R
install.packages("remotes")
remotes::install_github("itemresponsewarehouse/Rpkg")
library(irw)
df <- irw_fetch("nicoli_2025_defense_union", source = "conj")

# Python
pip install irw

import irw
df = irw.fetch("nicoli_2025_defense_union", source="conj")

How to cite

@article{Nicoli_2025, title={Citizen Support for a European Defense Union: An International Conjoint Experiment on Security Cooperation in Europe}, volume={69}, ISSN={1468-2478}, url={http://dx.doi.org/10.1093/isq/sqaf044}, DOI={10.1093/isq/sqaf044}, number={3}, journal={International Studies Quarterly}, publisher={Oxford University Press (OUP)}, author={Nicoli, Francesco and Burgoon, Brian and van der Duin, David}, year={2025}, month=June }

Version and provenance

IRW version	v584
Redivis dataset	irw_conjoint v4.2
Redivis dataset DOI	10.57761/qkye-q530
Manifest pin for this IRW version	v4.2
Metadata source	irw_meta v44.0