There’s no agency in the market. That’s the entire point of markets - being independent of a single human’s whims and being an equalizing force, the “invisible hand”.
And the entire point of communism is getting that agency, having production for the sake of humans rather than humans for the sake of production.
No, migration is caused by economics, so it only makes sense to use economics to talk about it. In capitalism, migration follows the market laws, i.e. people migrating to where they expect to be paid more.
I took basic Econ. My point is decisions are multi-faceted. We are not all slaves of the invisible hand 24/7 as it guides our every single decision.