Armed conflict exposure and trust: evidence from a natural experiment

Layer 1: Overview

This paper asks how individual-level exposure to internal armed conflict shapes social capital, specifically trust in institutions and trust in people. The question matters because trust is a core component of social capital that underpins cooperation, economic growth, financial development, political participation, and post-conflict recovery; yet the empirical literature is split between studies finding conflict erodes trust and studies finding “post-traumatic growth” that enhances pro-sociality. The authors argue prior work cannot cleanly identify causal effects because of non-random selection into exposure, attrition from migration/death, and confounding conflict-induced changes in the socio-economic environment.

The empirical strategy exploits a natural experiment in Turkey: mandatory conscription assigns every male citizen, via a lottery, to a military base, and a significant share are randomly sent to bases in the eastern/south-eastern conflict zone where the state has fought the PKK since 1984. By sampling ex-recruits who live in peaceful western districts, exposure during military service is the respondents’ only personal contact with the conflict, isolating individual-level effects from environmental confounds. Data come from a field survey of 5,024 randomly selected adult males in 29 western districts in summer/fall 2019 (response rate 83%); eligible men had completed service between 1984 and 2014. Only 5 respondents did not answer the military-service questions.

Two exposure measures are built. ACE (Exposure to Armed Conflict Environment) is the standardized number of combatant casualties in the county and during the period of a respondent’s service, drawn from the Turkish State-PKK Conflict Event Database; its variation comes from four exogenous components (birthdate-driven timing, regulation-driven duration, clash intensity, and lottery-assigned location). TDE (Traumatic Direct Experiences) is a binary indicator equal to 1 if the respondent was wounded in armed clashes or had someone around them killed/hurt; 2% reported being wounded and 15% reported others around them killed or hurt. ACE and TDE correlate only 0.25. Two trust outcomes: Institutional Trust (average of 14 five-point items: army, judiciary, parliament, TV, newspapers, parties, clergy, universities, environmental orgs, charities, police, banks, private companies, EU) and Social Trust (trust in unfamiliar people / strangers). The army was the most trusted institution (~75% high trust vs. 43% for courts, 35% for parliament). Estimation is OLS with age, education, and minority controls, standard errors clustered at the living-block level.

Main findings: the two exposure types have opposing effects. In the preferred specification including both measures, ACE raises Institutional Trust (about 0.02, significant at 5%) and Social Trust (about 0.03, significant at 5%), while TDE lowers Institutional Trust (about -0.15, 5%) and Social Trust (about -0.11, 1%). ACE is insignificant when TDE is omitted because it then pools traumatized and non-traumatized recruits, biasing it toward zero. There is no significant ACE-by-TDE interaction, so the negative trauma effect is independent of conflict intensity. Effects are similar in sign and magnitude across both trust dimensions, indicating an encompassing change rather than institution-specific distrust. Interactions with time-since-service are insignificant, implying the effects are permanent.

Mechanism: the authors invoke Janoff-Bulman’s (1992) “shattered assumptions” theory. TDE is positively associated with depression and insecurity indexes, which in turn correlate negatively with both trust measures; ACE is not significantly related to depression/insecurity. There is no significant relationship between exposure and trust in the army, ruling out an accountability mechanism. Heterogeneity by in-group: TDE raises trust in family (coping mechanism) but, like strangers, friends show positive ACE and (insignificant) negative TDE effects, arguing against parochialism as the main driver. Implications: distinguish contextual from direct exposure; design psychological recovery programs for veterans; estimates are likely conservative given the limited 6-18 month exposure window.

Layer 2: Deep Dive

What is the identification strategy and what are the main threats to it?

Identification relies on Turkey’s conscription lottery, which randomly assigns drafted men to military bases, a significant share of which lie in the eastern/south-eastern conflict zone. Because the sample is drawn only from peaceful western districts, service is the respondents’ sole exposure to the conflict, isolating individual-level effects from conflict-induced changes in the socio-economic environment. ACE’s variation comes from four exogenous components: birthdate-driven timing of service, regulation-driven service duration (18 months in the 80s, 15 in 1992, 18 in 1995, 15 in 2003, 12 in 2014), clash intensity around the base, and lottery-assigned location. Threats: (1) non-random base assignment - addressed by balance tests (Table 2) showing no systematic differences in age, ethnicity, or height by conflict-zone assignment; education differs because college graduates are slightly skewed toward western bases (40% of non-college-grads served in the east vs. 30% of college grads), but the difference vanishes when college graduates (9.3% of sample) are excluded, education is controlled in all specs, and a no-college-grad sample (Table A2) is robust; (2) self-selection into dangerous tasks/violence for TDE - addressed by the fact that task assignments are made by command at the start of service before behavior is observed, and Table 3 balance tests show wounded vs. non-wounded respondents do not differ on pre-military characteristics; an alternative TDE (observing a fellow soldier hurt/killed, immune to own risk-taking) yields similar results (Table A1).

What are the main mechanisms and how are they distinguished empirically?

The proposed mechanism is a transformation of fundamental world assumptions (benevolence, meaning, safety of the world) per Janoff-Bulman (1992). Distinguishing tests: (1) TDE affects a broad range of trust dimensions but is NOT significantly related to trust in the army, ruling out an accountability interpretation (which would predict distrust concentrated on state security institutions) and a comradeship interpretation (which would predict effects only on social trust). (2) TDE is positively and significantly associated with depression and insecurity indexes (Tables 7-8), and these indexes are themselves negatively and significantly related to both trust measures, consistent with shattered world assumptions. (3) ACE is not significantly associated with depression/insecurity; the authors note these scales are worded to detect negative states and may miss the positive feelings ACE could elicit, and that indirect environmental exposure plausibly has weaker effects on fundamental beliefs than direct trauma.

What heterogeneity is documented?

The central heterogeneity is by exposure type: contextual exposure (ACE) raises trust, direct trauma (TDE) lowers it. No significant ACE-by-TDE interaction, so trauma’s effect does not depend on conflict intensity. No significant moderation by time since service (Table 6), implying permanent effects. In-group heterogeneity (Table 9, ordered logit): TDE significantly raises trust in family (coefficient 0.26, 5%), interpreted as a coping mechanism of retreating to closest networks; trust in friends shows positive ACE (0.07, 5%) and negative but insignificant TDE, mirroring the stranger result. The similar pattern for strangers and friends argues against parochialism as the primary driver.

What robustness checks are run?

(1) Alternative TDE defined as observing a fellow soldier hurt/killed, more immune to own risk-taking (Table A1) - results unchanged. (2) Excluding college graduates (Table A2) - results unchanged. (3) Tobit specification accounting for the censored nature of trust measures (Table A3) - similar results. (4) Including a conflict-zone dummy and base-district fixed effects (Tables A4-A5) to absorb unobserved location heterogeneity (though the authors note these likely absorb part of the ACE variation, so they are not in the baseline). (5) Separate results for each of the 14 institutional-trust dimensions (Table A6) and excluding one dimension at a time from the composite index - results stable. (6) Alternative standard-error clustering at home-district or region levels - unchanged.

How does this paper relate to and differ from closely related prior work?

It builds on the draft-lottery natural-experiment tradition (Angrist 1990 on Vietnam; Angrist-Chen 2011; Galiani et al. 2011; Grossman et al. 2015) and the conflict-and-social-capital literature (Rohner et al. 2013; Cassar et al. 2013; Bauer et al. 2016; Kijewski-Freitag 2018). It differs by: (1) cleanly identifying causal effects free of environmental confounds, since trust is measured in untouched western locations rather than in transformed post-conflict settings; (2) carefully separating contextual from direct exposure, which many studies cannot; (3) proposing a novel individual-level psychological mechanism (shattered world assumptions) rather than the economic/institutional-legacy channels (Besley-Reynal-Querol 2014; Nunn-Wantchekon 2011; Grosjean 2014) or the inter-group-competition/parochialism explanation (Bauer et al. 2016). The authors argue the heterogeneity they document can help reconcile the conflicting positive and negative findings in prior literature - prior ‘pro-social’ effects may reflect coping-driven re-creation of safe social space (consistent with Grosjean’s (2014) ‘dark nature’ of conflict-induced pro-sociality), not genuine restoration of trust.

What are the policy implications and their scope conditions?

Two main implications: (1) researchers and policy advisers should carefully distinguish contextual from direct conflict exposure when studying behavioral outcomes; (2) the findings inform the design of psychological and social recovery programs for combat veterans and victimized post-conflict populations. Scope conditions: the study is specific to the Turkish conflict setting and limited to male ex-combatants; it remains open whether effects generalize to women, civilians, or other countries. Because exposure lasted only a pre-determined 6-18 months after which recruits returned to peaceful lives, the authors argue estimates are conservative relative to populations living in protracted conflict environments.

What additional findings or caveats are noted?

The authors report (results not shown) that individuals with traumatic experiences are more likely to participate in political organizations, and cite Kibris-Nelson (2021) that such individuals are more likely to start their own businesses (while being less successful at it), consistent with coping strategies of creating a controllable environment. They concede the mechanism evidence for the positive ACE effect is ‘somewhat less clear’ than for TDE, and offer an alternative possibility that whether intense-environment survival raises trust may be moderated by how heroically the veteran’s social network views his service. The depression subscale is the 6-item Brief Symptoms Inventory; insecurity is an 8-item scale. Roughly 6.5 million of the 15 million men drafted since 1984 are estimated to have served in the conflict zone.

Key Concepts

Exposure to Armed Conflict Environment (ACE): A standardized, individual-specific measure of contextual conflict exposure equal to the number of combatant casualties in the county and during the time period of a respondent’s military service. It captures immersion in the conflict environment with high geo-temporal precision and is treated as exogenous because its components (birthdate-driven timing, regulation-driven duration, clash intensity, lottery-assigned location) are outside the individual’s control.

Traumatic Direct Experiences (TDE): A binary indicator equal to 1 if a respondent was personally wounded in armed clashes or had someone around them killed or hurt during military service. It captures direct, personal experience of violence as distinct from mere presence in a conflict environment; in the sample 2% were wounded and 15% had others around them hurt/killed.

Institutional Trust: In the paper’s sense, the simple average of a respondent’s 5-point Likert trust ratings across 14 public and private organizations (army, judiciary, parliament, media, parties, clergy, universities, environmental orgs, charities, police, banks, private companies, EU) - deliberately broad so as not to over-weight state institutions directly tied to the conflict.

Social Trust: A generalized form of trust measured by how much a respondent trusts people they are not familiar with (strangers), rather than the vaguer ‘most people’ wording, chosen to minimize in-group/out-group and ethnic associations and isolate generalized trust in others.

Shattered assumptions: The paper’s operative mechanism, drawn from Janoff-Bulman (1992): people hold core assumptions that the world is benevolent, meaningful, and safe; traumatizing experiences shatter these positive assumptions, eroding deeply rooted trust - whereas surviving a dangerous environment without mishap can instead reinforce them. Trust, depression, and insecurity are treated as observable implications of these otherwise-unobservable world assumptions.

Parochialism / parochial altruism: The rival hypothesis (associated with Bauer et al. 2016) that conflict exposure increases in-group favoritism while eroding out-group trust. The paper tests and largely rejects it as the primary driver because ACE raises trust in both strangers and friends and the in-group (family) pattern does not match parochial predictions.