Between individual choice and system outcome sits the step Schelling made famous: aggregation. Choices sort; sorted choices become structure; structure then confronts the next chooser as their environment. This is the level of networks and culture — and the least measured leg of the whole chain.
Two projects work it: the dissertation’s second paper asks whether the partisan organization of attention spills over into the 97% of online life that isn’t news at all; and the epistemic elites work maps how expert conversations, transnational in reach, aggregate into networks segregated along national lines. Above sits supply & cues; below, selection & attention.