Impact of Social Media Influencers on Brand Trust and Purchase Intentions in Fashion Markets

Thesis Abstract

The rapid proliferation of social media platforms has transformed consumer-brand interactions, yet the mechanisms by which social media influencers shape brand trust and subsequent purchase intentions in the fashion sector remain underexplored in cross-market contexts. This study addresses the problem of inconsistent findings on the effectiveness of influencer marketing by examining how influencer credibility, parasocial interaction, and perceived authenticity influence brand trust, and how this trust translates into purchase intentions among fashion consumers. The aim is to quantify the direct and indirect effects of influencer-driven cues on consumer decision-making, and to identify contextual factors that moderate these relationships. The specific objectives are (1) to assess the impact of perceived influencer credibility (expertise, trustworthiness) on brand trust; (2) to examine the role of parasocial interaction (emotional bond, identification) in shaping brand trust; (3) to evaluate how perceived authenticity of influencers moderates the relationship between credibility and brand trust; (4) to determine the effect of brand trust on purchase intentions for fashion products; (5) to test whether perceived price fairness and fashion involvement moderate the effect of brand trust on purchase intentions; and (6) to compare these relationships across three fashion market segments fast fashion, premium streetwear, and luxury athleisure. A cross-sectional, quantitative survey research design will be employed. The population comprises fashion consumers aged 18–45 who actively follow at least one lifestyle or fashion influencer on Instagram or TikTok for product recommendations. A stratified random sample will be drawn from three market segments (fast fashion, premium streetwear, luxury athleisure) with 300 respondents per segment, yielding a total target sample size of 900. Valid responses from at least 70% of the completed surveys will be retained, resulting in an effective sample of approximately 630–720 respondents. Data will be collected through a structured questionnaire incorporating previously validated scales influencer credibility (expertise, trustworthiness), parasocial interaction, perceived authenticity, brand trust, purchase intentions, perceived price fairness, and fashion involvement. The questionnaire will be pretested with 30 participants and refined for reliability. Reliability and validity will be evaluated using Cronbach’s alpha, composite reliability, and average variance extracted (AVE). Confirmatory factor analysis (CFA) will assess the measurement model, while structural equation modeling (SEM) will test the hypothesized relationships. Mediation analyses will examine whether brand trust mediates the effect of influencer credibility and parasocial interaction on purchase intentions. Moderation analyses will test the moderating roles of perceived authenticity, perceived price fairness, and fashion involvement. Multi-group SEM will compare path estimates across the three market segments to ascertain differential effects. Additionally, hierarchical regression will be used as a robustness check for the moderation effects. Theoretical grounding will draw on Social Influence Theory, the Source Credibility Theory, and the Theory of Planned Behavior, with integration through a process model that links influencer cues to brand trust and ultimately to purchase intentions. Key expected findings include (i) a positive effect of influencer credibility on brand trust, strengthened by higher parasocial interaction; (ii) perceived authenticity will strengthen the credibility–brand trust link, while lower authenticity weakens it; (iii) brand trust will significantly predict purchase intentions, with stronger effects in premium segments than fast fashion; (iv) perceived price fairness and fashion involvement will moderate the brand trust–purchase intention relationship, enhancing effects for higher involvement segments. The study contributes to knowledge by delineating the pathways through which influencer marketing affects consumer decision processes in fashion, clarifying the roles of credibility, authenticity, and parasocial interaction, and highlighting segment-specific dynamics with practical implications for marketers regarding influencer selection, content strategy, and pricing communication. The main conclusion is that influencer marketing is most effective when influencers are perceived as credible and authentic, fostering genuine brand trust that translates into purchase intent, especially among highly involved fashion consumers in premium segments. Recommendations include (1) brands should align with influencers whose perceived authenticity matches brand values; (2) tailoring content to deepen parasocial bonds while transparently disclosing sponsorship; (3) segment-specific strategies that emphasize value proposition and price fairness for different fashion segments; and (4) ongoing measurement of trust-building cues to optimize influencer campaigns.