Arrow's Impossibility Theorem

An Interactive Exploration — 3 Voters, 3 Alternatives
The Axioms
Unrestricted Domain (U)

Every logically possible profile of strict preference orderings is in the domain of the social welfare function.
Weak Pareto (WP)

If every voter prefers x to y, then the social ordering must rank x above y.
Independence of Irrelevant Alternatives (IIA)

The social ranking of x vs. y depends only on how each voter ranks x vs. y — not on how they rank any third alternative z.
Non-Dictatorship (ND)

No single voter always determines the social outcome: there is no voter i such that for all profiles, the social ordering equals i's ordering.
How to use: Choose a preset rule below to auto-fill the social welfare function and see which axioms it violates, or manually assign outputs row by row. The description panel explains each rule and previews its axiom status.
Choose a Rule

Social Welfare Function Table
Make selections to begin checking axioms.
# Voter 1 Voter 2 Voter 3 SWF Output Status