Jean-Jacques Rousseau’s public opinion theory

It’s pretty well known that Rousseau thought that the public was always right. But while reading On the Social Contract translated by Donald A. Cress, I came upon this less frequently discussed quote:

“The former [‘will of all’] considers private interest and is merely the sum of private wills. But remove from these [private] wills the pluses and minuses that cancel each other out, and what remains as the sum of differences is the general will,” which Rousseau claims in the previous paragraph is “always right” and tends towards the “public utility.”

This is an interesting public opinion theory. It assumes that aggregate public opinion has two components – a selfish and biased component and a component that produces the “right” public policy. The difference between the optimal policy and the median voter’s policy is due not to ignorance or systemic error, but to selfish desires that undermine the provision of public goods. If readers know of a published formal model of this theory, or applications of this theory, feel free to email me.