Steven Levitt, of Freakonomics fame, considers the case of the Minnesota teen who tried to sell his vote on eBay:
This guy’s hijinks did, however, give us a glimpse into the market price of a vote.
The minimum bid was set at $10. Nobody bid on his item. The failure to attract bidders is consistent with the arguments that Dubner and I have made about the puzzle of why people vote. Any individual’s vote is almost certain not to determine a presidential election (especially if that vote is cast in a state like Minnesota). Thus, the market price for that vote should be essentially zero. Certainly well below ten dollars.
Now, Levitt admits that the incentive not to sell your vote is pretty high, what with the felony charge and all. But Levitt misses the key point here, which is that, in a secret ballot election, there’s no way to prove that you indeed voted the way you claim you did. I’m no economist, but I’m pretty sure that, if there’s no way to check that a transaction went through, the value of the product tends to zero pretty darn quickly.
And that is exactly the point of secret-ballot voting. It’s not that people won’t attempt to sell their vote. It’s that there’s no way for them to prove they fulfilled their end of the deal. So a rational buyer won’t even try, because what’s the point?
In fact, back when we didn’t have the secret ballot in the 1800s (in fact all the way until the 1890s), people did sell their votes, sometimes in exchange for a few drinks. So the price of a secret ballot may indeed be 0, but the price of a public ballot almost certainly wouldn’t be. Yet another important reason why democracy needs the secret ballot.