The Legacy of Conflict on Socioeconomic Dynamics and Human Behavior: Evidence from Portugal’s Veterans of War

Last registered on May 04, 2026
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Pre-Trial

Trial Information

General Information

Title
The Legacy of Conflict on Socioeconomic Dynamics and Human Behavior: Evidence from Portugal’s Veterans of War
RCT ID
AEARCTR-0018517
Initial registration date
April 29, 2026

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
May 04, 2026, 8:08 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

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Primary Investigator

Name
João Pereira Dos Santos
Affiliation
ISEG - Lisbon School of Economics and Management
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Other Primary Investigator(s)

PI Name
José Tavares
PI Affiliation
Nova SBE
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PI Name
Luciano Amaral
PI Affiliation
Nova SBE
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PI Name
Henrique Pita Barros
PI Affiliation
ISEG
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Additional Trial Information

Status
On going
Start date
2026-04-29
End date
2026-09-01
Keywords
Behavior, Post-conflict
Additional Keywords
JEL code(s)
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This project studies how past exposure to violent conflict affects beliefs, preferences, and attitudes in later life. We implement a randomized priming design among Portuguese veterans of the Colonial War (1961–1974), a population for whom exposure to conflict is both historically meaningful and individually heterogeneous.
We design and conduct a randomized priming experiment within a large-scale survey of Portuguese war veterans. The experiment exploits variation in the ordering of survey modules to manipulate the salience of conflict exposure at the time respondents report attitudes and preferences. All respondents first complete a set of baseline modules collecting socio-demographic and health information. After these initial modules, respondents are randomly assigned to one of two groups that differ in the ordering when which they receive the subsequent block of the questionnaire.
The study is designed and conducted in partnership with the Liga dos Combatentes (Liga), the largest and most representative association of Portuguese war veterans.
External Link(s)

Registration Citation

Citation
Amaral, Luciano et al. 2026. "The Legacy of Conflict on Socioeconomic Dynamics and Human Behavior: Evidence from Portugal’s Veterans of War." AEA RCT Registry. May 04. https://doi.org/10.1257/rct.18517-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
We embed a randomized priming experiment within a large-scale survey of Portuguese war veterans.
The experiment exploits variation in the ordering of survey modules to manipulate the salience of conflict exposure at the time respondents report attitudes and preferences. All respondents first complete a set of baseline modules collecting socio-demographic and health
information. After these initial modules, respondents are randomly assigned to one of two groups that differ in the ordering when which they receive the subsequent block of the questionnaire.
Intervention Start Date
2026-04-29
Intervention End Date
2026-09-01

Primary Outcomes

Primary Outcomes (end points)
Trust (generalized and institutional)
Attitudes toward out-groups
Policy preferences
Mental health and well-being
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We embed a randomized priming experiment within a large-scale survey of Portuguese war veterans.
The experiment exploits variation in the ordering of survey modules to manipulate the salience of conflict exposure at the time respondents report attitudes and preferences. All respondents first complete a set of baseline modules collecting socio-demographic and health
information. After these initial modules, respondents are randomly assigned to one of two groups that differ in the ordering when which they receive the subsequent block of the questionnaire.
Experimental Design Details
Not available
Randomization Method
Randomization done in office by a computer
Randomization Unit
Our unit of observation will be the individual. We are collecting data from several offices of Liga around Portugal
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
We will collect information on the Liga offices around the country.
Sample size: planned number of observations
Close to 2000 respondents
Sample size (or number of clusters) by treatment arms
50% vs 50%
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
Nova SBE Comissão de ética
IRB Approval Date
2025-04-10
IRB Approval Number
Approval Reference #25154
Analysis Plan

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