Social media engagement and participation intention in humanitarian logistics contexts: the mediating role of trust

Purpose As humanitarian organizations increasingly rely on digital platforms to engage and mobilize the public, this study aims to draw on the Stimulus–Organism–Response (S–O–R) framework to examine how social media engagement and perceived logistics efficiency are associated with participation intention, with trust as the internal evaluative mechanism. Design/methodology/approach A cross-sectional survey of 574 social media users in Egypt with prior exposure to humanitarian organizations’ online content was analyzed using confirmatory factor analysis and structural equation modeling in IBM AMOS. Indirect associations were estimated using 5,000 bootstrap resamples with bias-corrected and percentile 95% confidence intervals. Findings Trust was positively associated with participation intention. Social media engagement was associated with intention mainly through the direct pathway; its small indirect effect through trust was significant under bias-corrected but not percentile bootstrap intervals. Perceived logistics efficiency had a significant total association with intention but no significant direct association; approximately 94% of its total association ran through trust, although this indirect effect was not statistically significant at the 95% level. Practical implications Humanitarian organizations should manage social media as a participation pathway, combining interactive communication with transparent reporting of logistics performance to strengthen trust and intended public support. Originality/value The study distinguishes communication-based and operation-based cues within an S–O–R model of humanitarian participation intention, showing that trust accounts for a substantially larger share of the logistics-efficiency association than of the social-media-engagement association, without establishing causal pathways.