Who legally owns the right barely matters if bargaining is free

Ronald Coase argued that when a factory's pollution harms a neighbor, the law doesn't need to pick a side: if both parties can bargain cheaply, they'll strike a deal reaching the efficient outcome regardless of who holds the legal right. His real point was the reverse — since real transaction costs are rarely that low, who gets the right, and how laws assign it, ends up mattering enormously.

— Ronald H. Coase, The Problem of Social Cost — Journal of Law and Economics, Vol. 3, 1960, pp. 1-44