The "nirvana fallacy"....................

Demsetz constantly stressed the dangers of falling prey to the “nirvana fallacy,” or the view of public policy that “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.” 

-Richard Epstein, from his article, The Greatness of Harold Demsetz

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