Predicting the NYC Mayoral Race

Yesterday, co-blogger Jeremy asked “Should Andrew Yang Wait To Concede?” in the New York City mayoral race. He argued that while Yang finished 4th in 1st-place primary votes, the new Ranked Choice Voting system meant he could still win. This is of course true in theory- but today I argue it is very unlikely in practice.

I say this not because I have scrutinized all the polls to predict the exact distribution of 2nd- and 3rd-place votes, or because I think I know more than Jeremy about political science or New York. Instead, any time I’m wondering about whether something will happen and I don’t have a strong opinion based on my own knowledge, I simply check what markets have to say. In this case, there are prediction markets bearing on this exact issue. The odds from PredictIt, shown below, have Adams (who finished with the most 1st-place votes, 32%) as the heavy favorite, with Yang reduced to an approximately 1% chance of winning.

But Jeremy is right to highlight that the Ranked-Choice system makes it less obvious who will win. You can see PredictIt traders still think that Garcia, who finished with 19% of 1st-place votes, is substantially more likely to win than Wiley, who finished with 22% (though the new system didn’t matter in the Republican primary, where Sliwa won with a clear majority of 1st-place votes).

Crypto-based betting platform Polymarket has actually closed their market for Yang already, declaring that he lost, though they agree with PredictIt that the overall election isn’t over and that Garcia still has a real chance despite coming in 3rd for 1st-place votes.

Of course, prediction markets aren’t perfect- they are certainly less accurate (easier to beat) than the stock market, as my track record of betting in both shows. But they make for a great first approximation on subjects you don’t know well, and if you think you do know better, they offer you the chance to make money and to make the odds more accurate. If you think Yang will still win, you can go bet on PredictIt and potentially 100x your money. Or if you think this ranked choice stuff is nonsense and Adams obviously won, you can pick up an easy 10% return. Or if you’re like me in this case, you can stay out of it, take a quick glance at the markets, and get a good idea of what is likely to happen without having to read the news or the pundits.

Should Andrew Yang Wait to Concede?

Yesterday New York City held their mayoral primary elections. This was an exciting event for election system nerds (political scientists and public choice economists) because NYC is now using a form of ranked choice voting to determine the winner.

While this is not the first place in the US to use RCV (Maine, Alaska, and a handful of cities use it), it is still notable for a few reasons. First, this is America’s largest city. Second, there are a lot of viable candidates, which makes RCV especially interesting and useful.

Specifically, NYC is using a form of voting called instant runoff. There are currently 13 candidates, and voters indicate their top 5 in order. If no one has a majority (>50%) of the votes, then the rankings entered by voters come into play. And indeed that is what happened yesterday.

On the first round, only counting first place votes, Andrew Yang came in 4th with just under 12% of the votes. So last night he conceded.

But should Yang have conceded? Maybe not! Let’s explore how instant runoff works.

Continue reading