Quadratic Voting in the Field

The Democratic caucus in the Colorado state legislature wanted to get their member’s feedback on the bills most important to them. That’s hard to do because each member has an incentive to claim that their pet bill is by far the most important bill to them. Thus, Chris Hansen, the chair of the House Appropriations Committee, who also happens to have a PhD in economics, decided to use a modified form of quadratic voting. Each voter was given 100 tokens to vote and the price of x votes for a policy was x^2 so you could buy 10 votes on your favorite policy for 100 but you could also buy 5 votes on each of your four favorite policies (5^2+5^2+5^2+5^2=100).

Wired: So in mid-April, the representatives voted. Sure, each one could have put ten tokens on their pet project. But consider the or: Nine votes on one (cost: 81 tokens) but then three votes on another (cost: nine tokens). Or five votes each (25 tokens) on four different bills!

In Colorado at least, it worked, kind of. “There was a pretty clear signal on which items, which bills, were the most important for the caucus to fund,” Hansen says. The winner was Senate Bill 85, the Equal Pay for Equal Work Act, with 60 votes. “And then there’s kind of a long tail,” Hansen says. “The difference was much more clear with quadratic voting.”