Liberal Paradox

A logical paradox advanced by Amartya Sen, building on the work of Kenneth Arrow and his General Possibility Theorem, that showed that within a system of menu independent social choice, it is impossible to have both a commitment to "Minimal Liberty", which was defined as the ability to order tuples of choices, and Pareto Optimality.

Since this theorum was advanced in 1970, it has attracted a wide body of commentary from philosophers such as James M. Buchanan and Robert Nozick among many others.

The most contentious aspect is that it seems, on one hand, to contradict the libertarian notion that the market mechanism is sufficient to produce a Pareto optimal society – and on the other hand it argues that degrees of choice and freedom, rather than welfare economics should be the defining trait of that market mechanism. As a result it attracts commentary from both the left and the right of the political spectrum.