Rising polarization is taking place because there is now a fundamental disagreement across our society concerning who has the property rights to different resources.
While Kahn is correct about property rights being at the core of the dispute, he glosses over the real issue by going off to discuss game theory and bargaining. That real issue is how different groups in society gained those property rights, whether its entitlement to jobs or use of natural resources or control of social mores. Much of these property rights were gained through coercion of some form, such as slavery, land grabs or paternalistic social structures. Resolving these requires agreeing first on basic societal morality and ethics, and then turning to how to resolve the redistribution of those rights, rather than just plunging straight into bargaining.