Externalities and market freedom are completely different concepts.
A free market does not allow you to dump your garbage on public property, and no economist has ever argued that.
A free market does not allow you to dump your garbage on public property, and no economist has ever argued that.
Libertarians generally argue that externalities should either be illegal or taxed, when there are no other practical solutions. Here's a video of Milton Friedman on the topic: https://www.youtube.com/watch?v=0YGfwSvLkC0
on edit: huh, I didn't know about British economist William Forster Lloyd, mentioned in the article, so I guess at least one economist has argued that it will happen (not though, that it is 'allowed' by)