Daily Archives: February 22, 2017

Kenneth Arrow’s (Ignored) Impossibility Theorem

By William K. Black
February 22, 2017     Bloomington, MN

Kenneth Arrow, one of the giants of economics, has died at the age of 95.  He became a Nobel Laureate in 1972.  As a young lawyer in 1977, I saw him in action as an expert witness on the subject of risk.  The context was setting the rates for shipping oil through the Trans-Alaska Pipeline System (TAPs).  Arrow testified about the risks of oil prices falling.  The FERC administrative law judge thought such a scenario was ridiculous.  Within four years, oil prices fell sharply.  Arrow’s experience was a common one for economists dealing with lawyers – the ALJ ignored him.

The New York Times obituary for Arrow is revealing about how the conventional wisdom distorts economic theory in a predictably skewed fashion.  It begins by discussing Arrow’s “impossibility theorem,” which states that where there are more than two choices it is impossible to construct perfect majority choice systems.

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