Abstract: Gratitude expression is ubiquitous in interpersonal interactions. Prior research has primarily examined its positive effects from the perspective of a single interactions or a single actor, with limited attention to its dynamic evolution in ongoing interactions. Notably, in tourism service interactions, gratitude expression is particularly likely to be continually acknowledged, reciprocated, and amplified across multiple rounds of interaction, because tourism services are characterized by open expression norms, reciprocal and continuous interaction, and network connectivity. However, existing theories are largely based on static, linear causal logic and struggle to explain how gratitude expression continuously amplifies its influence through bidirectional feedback and role switching.
In response, this manuscript proposes the echo effect of gratitude expression, which re-conceptualizes gratitude expression from a one-time emotional event into an ongoing interaction process. The echo effect is defined as a dynamic phenomenon in which gratitude expression, grounded in bidirectional feedback within a core interaction dyad, progressively extends its influence across multiple rounds of interaction and role transitions. This concept further distinguishes between two levels: direct echo cycles (bidirectional feedback within the same interaction dyad) and cross-actor echo expansion (the transfer of influence to other interaction partners).
Building on this conceptualization, this manuscript develops two modules comprising three studies. Study 1 focuses on theoretical construction. It proposes four core propositions that elucidate a closed-loop mechanism: gratitude expression→positive responsiveness→reciprocal gratitude expression→sustained positive responsiveness. This framework integrates role switching and network connectivity as key conditions for expansion, thereby establishing an integrated theoretical model of the echo effect of gratitude expression.
Study 2 focuses on the tourist-to-employee pathway. Drawing on conservation of resources theory, this study will reveal how tourist gratitude expression alleviates employee emotional exhaustion and enhances service performance through two parallel mechanisms: cognitive reappraisal (reframing service work as meaningful contribution) and emotional energy (accumulating positive affect from gratitude encounters). These mechanisms may help employees recover from emotional depletion and sustain high-quality service delivery.
Study 3 focuses on the employee-to-tourist pathway. Grounded in construal level theory, this study will examine how identity cues in employee gratitude expression (individual identity vs. collective identity) influence tourist responses. Individual-identity expressions may reduce tourists’ psychological distance from employees, enhance their perceived closeness to the employee, and thus promote immediate reciprocal behaviors (e.g., tipping, positive reviews). Collective-identity expressions may increase psychological distance, yet they enhance brand reliability perceptions and foster long-term loyalty. Furthermore, perceived sincerity of gratitude expression may be introduced as a critical boundary condition, moderating the effects of gratitude expression on tourist responses.
The theoretical contributions of this manuscript are fourfold. First, it proposes the original concept of the echo effect of gratitude expression, shifting gratitude research from a static, single-interaction perspective to a dynamic, multi-round, bidirectional interaction perspective. This represents a fundamental reconceptualization of how gratitude operates in ongoing social exchanges. Second, it reveals the accumulation-expansion mechanism of gratitude expression in continuous interactions, moving beyond existing linear causal models to explain how seemingly minor gratitude expressions can generate progressively larger effects over time and across interactants. Third, it will identify and test two distinct pathways—tourist-to-employee and employee-to-tourist—each with different underlying mechanisms. This dual-pathway design provides a more comprehensive and integrative theoretical account of emotional expressions in service contexts. Fourth, by leveraging the unique features of the tourism service setting—including open expressive norms, interactional reciprocity and continuity, and network connectivity—this manuscript offers new theoretical insights and empirical avenues for understanding the sustained role of emotional expressions in service ecosystems. The echo effect is not merely a dyadic phenomenon but can propagate across broader service networks.
Practically, this manuscript provides actionable guidance for tourism organizations to optimize emotional interaction management, enhance service experiences, and facilitate value co-creation. By understanding how gratitude expressions can be strategically initiated and reciprocated, organizations can foster positive emotional climates, reduce employee burnout, and build lasting customer loyalty.

Key words: gratitude expression, echo effect, tourism, tourists, employees