It was a few years ago now that I introduce these structural ideas of capitalism as a system subjected to simultaneous influences of public and private interests at every transaction. My first approach was to make the argument that pure public goods really don’t exist. The classic example of the lighthouse, which provides a seemingly non-excludable benefit by beaming its bright lights across the water, can be taken private. As can virtually all goods.
More evidence that public goods, as classically defined, falls apart under scrutiny is fully unpacked here in Our Problem is a Problem of Design. (Wow, written some four years ago. Where does the time go?)
But the lighthouse, along with any other good, can have degrees of public and private holds on their value. And so it isn’t the nature of the good which determines it’s ownership, but the way that it is used by individuals or groups of individuals. The division of capitalism as the system of private interests and politics as the system of public interests isn’t the correct demarcation.
The division is that capitalism is a comprehensive economic system of public and private interests, where the actors simultaneously evaluate their private and their group (public) interests at time of transaction. The mechanism in each sphere is different but the end choice is a blend of the two. The division puts politics in a separate arena which handles the style and substance of governance.