See "'Instant-Runoff' Voting Leaves Room for Campaign Strategy" to read more about how instant-runoff voting could impact this year's election.

Befitting a place known for adding complexity to seemingly trivial tasks, the votes cast by Harvard students in the Undergraduate Council presidential race will go through an elaborate algorithm before a winner is determined.

Unlike most American elections, where the candidate who wins is simply the one with the most votes, the UC candidate with the most first-place votes does not automatically win the election.

Instead, the UC uses a system where voters are allowed to rank their preferred candidates instead of voting for a single one—a system that many experts say better represents voters’ true preferences.

Voters using the process, known as “instant-runoff voting,” list presidential tickets in order of preference. The first-choice votes are tallied, and a ticket that holds a majority of these votes is declared the winner.

But if no ticket wins a majority of the first-place votes, the ticket with the least number of votes is eliminated and its votes are redistributed to the second-place votes on the ballots. This process continues until a candidate wins a majority.

Instant-runoff voting—which has its origins in a system developed in the 1850s by Thomas Hare of England and Carl Andrae of Denmark—is advantageous because voters are free to choose more marginal candidates who may not have the strongest chance at winning. Under a standard plurality voting system, voters are often pressured to choose mainstream candidates for fear that their votes would be wasted on less viable candidates.

The instant-runoff system also ensures that the candidate who ultimately wins the election ends up with a majority of the votes, increasing the legitimacy of the winning ticket.

But the system comes with disadvantages as well, principally that instant-runoff voting is often difficult to understand and may confuse voters.

And for most jurisdictions, implementing an instant-runoff scheme is more expensive and time-consuming because it requires multiple simulated runoffs. This drawback is not a critical concern for the UC, however, as the adoption of electronic voting has made the council’s elections easy to administer.

Last year, the UC presidential election required four rounds of eliminating candidates and redistributing votes before Ryan A. Petersen ’08 and Matthew L. Sundquist ’09 were elected. This year’s election can only have one runoff since there are only three tickets.

The instant-runoff system is a popular one at elite college campuses throughout the country, with student government elections at Dartmouth, Princeton, MIT, and Stanford using the system.

The city of Cambridge also uses a variant of instant-runoff voting to elect its nine city councillors and six School Committee members.

—Staff writer Roger R. Lee can be reached at rlee@fas.harvard.edu.