Local Independence of Irrelevant Alternatives - Voting Theory

Voting Theory

In voting systems, independence of irrelevant alternatives is often interpreted as, if one candidate (X) wins the election, and a new candidate (Y) is added to the ballot, only X or Y will win the election.

Approval voting and range voting satisfy the independence of irrelevant alternatives criterion. Another cardinal system, cumulative voting, does not satisfy the criterion.

An anecdote which illustrates a violation of this property has been attributed to Sidney Morgenbesser:

After finishing dinner, Sidney Morgenbesser decides to order dessert. The waitress tells him he has two choices: apple pie and blueberry pie. Sidney orders the apple pie. After a few minutes the waitress returns and says that they also have cherry pie at which point Morgenbesser says "In that case I'll have the blueberry pie."

All voting systems have some degree of inherent susceptibility to strategic nomination considerations. Some regard these considerations as less serious unless the voting system specifically fails the (easier to satisfy) independence of clones criterion.

Read more about this topic:  Local Independence Of Irrelevant Alternatives

Famous quotes containing the words voting and/or theory:

    Common sense should tell us that reading is the ultimate weapon—destroying ignorance, poverty and despair before they can destroy us. A nation that doesn’t read much doesn’t know much. And a nation that doesn’t know much is more likely to make poor choices in the home, the marketplace, the jury box and the voting booth...The challenge, therefore, is to convince future generations of children that carrying a book is more rewarding than carrying guns.
    Jim Trelease (20th century)

    Hygiene is the corruption of medicine by morality. It is impossible to find a hygienest who does not debase his theory of the healthful with a theory of the virtuous.... The true aim of medicine is not to make men virtuous; it is to safeguard and rescue them from the consequences of their vices.
    —H.L. (Henry Lewis)