Ribeiro, TiagoAlmeida, Victor Manoel Cunha de2026-05-292026-05-292024-12-241618-4742http://hdl.handle.net/10400.1/29059Research question: Joint events uniting multiple cities or nations seem to guide FIFA’s choice for hosting future mega-events. In response to this challenge, new principal–agent social insights are shaping citizen support. This study investigated the determinants of Portuguese resident support for the 2030 FIFA World Cup within the framework of the agency and social exchange theories. Research methods: A sequential explanatory mixed-methods design was used to examine Portuguese resident perceptions towards the 2030 FIFA World Cup. This involved an initial quantitative phase using structural equation modelling (n = 402) followed by a qualitative strand comprising two focus groups (n = 16) to develop inferences from the findings. Results and findings: The results indicate that a country’s sport federation is a key agent that can attract and influence resident behaviour, while the relations with the government are weakened within the co-hosted event context. The findings confirmed that the principal–agent symbiotic dynamic can strengthen the exchange relationships and subsequently influence their support intentions to the event. The qualitative strand provided rationale for the results, emphasizing the shortcomings in agency relationships and minimizing the social value attributed to the support process in co-hosted events. Implications: This study enhances our understanding complementarity between agency and social exchange theories, clarifying the real value attributed by the host residents to a co-hosted event. Moreover, our findings offer valuable information for event bidders and local governments, especially when decisions are made without public consent that socially impact the host community.engPublic supportAgency theorySocial exchangeFIFA World CupPortugaljournal article10.1080/16184742.2024.24383891746-031X