Determinants of Source Credibility in Terms of Herd Behaviour and the Anchoring Effect: The Case of Instagram Influencers

The objective of this paper is to explore the effects of herding and anchoring effects, two behavioural economics concepts, on perceived source credibility, which is commonly utilized in marketing research. These cognitive shortcuts that shape consumers' decisions reduce their perceived risk or help them make decisions under uncertainty. The literature contains a limited amount of research on the topic that addresses source credibility in terms of behavioural economics. Within this framework, the study is anticipated to enhance the body of literature through its chosen topic and methodology. When reviewing research undertaken within the marketing domain, the experimental design method has been used in very few studies. In this context, in the experimental designs created within the scope of the study, various scenarios were designed on the basis of follower number (high/low) to evaluate the impact of herd behaviour on the credibility of the source and on the substance of news about the influencer (positive/negative) to measure the anchoring effect. After the participants were shown one of the scenarios, they were given questionnaires with statements about source credibility to answer, and how the perception of source credibility differs according to herd behaviour and the anchoring effect was investigated. Instagram influencers were used in the experimental designs created in the study because Instagram application is increasingly preferred over other social media platforms, is more effective in terms of marketing communication, is increasingly included in the marketing strategies of businesses and is preferred by the young population. Within the framework of this research, data were gathered via an online survey administered to a total of 727 students enrolled in various departments across universities in Turkey. These data were subjected to one-way ANOVA via the SPSS program. Research findings indicate that herding behaviour significantly affects the perceptions of the source credibility, expertise, and attractiveness of social media influencers. Furthermore, anchoring significantly affects the source credibility perceptions and expertise, trustworthiness, and attractiveness subdimensions. However, in scenarios where the number of followers and anchors are identical, a statistically significant difference was not found in the perception of source credibility in relation to the gender of the influencer.