We must now think the unthinkable. Such is the Brexit train wreck, the possibility of Jeremy Corbyn as prime minister has increased significantly.

Imagine travelling back in time to early 2015 to warn of this impending disaster. Most then would guffaw at the idea of this old, unreconstructed socialist being a Labour leadership candidate, let alone a PM. With questionable friends and worse public policy takes, few could have predicted his rise to the cusp of power.

Yet there he and his comrades stand. If they reach the summit, one factor behind his success will be that Corbyn’s approach gives him an advantage in debate over those committed to liberal democratic capitalism. For unlike those of us who believe in the messy reality of market-based exchange and its regulation, his world view simply denies trade-offs and that real-world imperfections need exist. This isn’t a surprise: socialism is the ultimate manifestation of what is known as the “nirvana fallacy”.

In a classic 1969 article, the University of Chicago economist Harold Demsetz (who sadly passed away this week) coined that phrase. He explained: “The view that now pervades much public policy economics implicitly presents the relevant choice as between an ideal norm and an existing ‘imperfect’ institutional arrangement. This nirvana approach differs considerably from a comparative institution approach in which the relevant choice is between alternative real institutional arrangements.” Is there a better description of Corbyn’s naive socialism, which promises to perfect society to eliminate injustice, poverty and class; and to do so, at least implicitly, without other material consequences?