Behind Closed Doors: Exploring Informal Mechanisms of Interest Group Influence During Coalition Negotiations

Research on interest group influence has traditionally focused on lobbying strategies and information exchanges within established policy arenas such as committee hearings, public consultations, or formal meetings with legislators (e.g., Binderkrantz et al., 2014; Cross et al., 2021; De Bruycker & Beyers, 2019). These studies emphasize the significance of organizational and contextual factors, including resources and issue salience, in shaping influence. However, existing research largely overlooks the stage of government formation, especially coalition negotiations, which happen behind closed doors and leave few observable traces. Nevertheless, understanding influence during this stage is crucial, as coalition agreements determine the policy agenda for the entire legislative session (Willems & Beyers, 2023). Some studies started to address this gap. Romeijn (2021) examined, in the Dutch case, whether interest groups succeed in translating their policy preferences into coalition agreements, drawing on the policy briefs they submit to the negotiating parties. But it remains the exception. More broadly, research on interest groups’ influence on political parties (e.g., Røed, 2022, 2023; Røed et al., 2023) highlights factors such as organizational elements—including group and party types (niche vs. mainstream, governing or opposition)—issue ownership, as well as contextual factors like issue salience, and relational predictors such as (historical) organizational ties and ideological proximity between interest groups and parties. While these studies shed light on key determinants of influence, they primarily focus on static traits rather than on the dynamic, relational processes that occur during coalition negotiations or between interest groups and parties in general. This paper shifts focus to informal, relational mechanisms. Personal connections and informal interactions are widely recognized as important in lobbying, yet their impact on influence remains underexplored. Although experimental work on social lobbying (Grose et al., 2022) shows that informal interactions—such as dinners or casual meetings—can shape policymakers’ receptivity to interest groups’ demands. Its findings suggest that informal, relational mechanisms operate alongside static, structural factors. This informality is especially relevant in systems with dense networks of parties and interest groups, where access and influence are often limited to a small group of insiders. Building on these insights, this paper explores how informal exchanges and personal connections shape interest group influence during coalition negotiations following the June 2024 elections at both the federal and Flemish levels in Belgium. Using interviews with interest group representatives and politicians involved in the negotiations, the study explores how informal, relational mechanisms interact with classic predictors of influence, and how trust and (historical) organizational ties enable influence beyond formal lobbying channels. The paper contributes to the literature in two ways. First, it expands research on interest group influence to the less-studied stage of coalition negotiations. Second, it goes beyond traditional predictors to examine how informal interactions and personal connections shape influence. Normatively, the paper emphasizes the democratic implications of a system where a small number of key insiders may disproportionately determine policy outcomes in a closed negotiating setting. Ultimately, this study enhances our understanding of early-stage policy-making and the subtle mechanisms through which interest groups exert influence.