How Clustered Ideological Landscapes Emerge Through Opinion Dynamics

An agent-based interaction model employing homophile adaptation and reassessment is shown to explain how political landscapes in one-dimensional ideology space might evolve. Empirically, left-right self-placements are often not normally distributed but have multiple peaks (e.g. extreme-left-center-right-extreme). This distribution may also change over time. In the model, agents repeatedly adjust their ideological position in their ideological neighborhood and sometimes completely reassesses it depending on their ideological openness and their propensity for reassessment, respectively. Simulations show that this leads to the emergence of clustered ideological landscapes similar to the ones observed empirically. Counterfactual changes in the model parameters show that the ideological landscapes are susceptible to both slow and abrupt changes. This extends the classical spatial model of electoral competition with a dynamic element taking into account that voters themselves shape the political landscape by adjusting their positions and preferences through interaction.