There’s a nice post today from the Wall Street Journal Numbers Guy about the new voting system for the Oscars. Since they increased the number of Best Picture nominees from five to ten, they’ve scrapped the “vote for a single film; the film with the most votes wins” system:

The new system for best-picture voting is just like the procedure for selecting nominees. It’s called single transferable vote and is similar to an instant-runoff election. Voters will rank the 10 nominees from 1 to 10. PricewaterhouseCoopers staffers who oversee the voting for the Academy will place the ballots into 10 piles, each one for ballots with one of the films ranked at the top. If one pile has 50% of the ballots, it wins. If not, the ballots in the smallest pile are added to the pile of the second-place film listed, and the procedure continues until one film has 50% of the votes.

I like ranked ballots because they are simple: voters need to write down a lot of information, but it’s information they can readily understand and communicate. The primary alternative for voting among more than two choices is the use of approval ballots, on which voters just pick a subset of the nominees they wouldn’t mind winning (without ranking them); the standard single-choice ballot is just a special case of approval ballots where you can only approve of a single nominee. Approval ballots encode less information but paradoxically make the voting process a lot more complicated. How do you decide what your threshold is for approval? If you think several nominees are acceptable but that one is much much better than the others, should you only approve of the one you think is far superior? The answers to these questions depend on not just your opinion of the nominees, but also your expectations about other voters’ behavior.

The instant-runoff method of tabulating ranked ballots, of course, is also vulnerable to certain types of strategic voting, whereby voters are best served by submitting a ballot whose ranking does not accurately reflect the voter’s preference. Beyond the fact that such opportunities are quite rare in practice, I don’t think that’s such a big deal in the long term. It’s the interface with voters that needs to be understood and adopted by all members of the Academy; that’s where the inertia in the system resides. Instant-runoff is the easiest tabulation system to explain, so it makes everyone more comfortable with ranked ballots during the changeover. Once voters are accustomed to such ballots, changing the way the ballots are tabulated to choose a winner is straightforward and inexpensive. A Condorcet tabulation method would eliminate the rare cases where misrepresenting your preferences on your ballot would be of benefit.