Prediction: Cruz Wins Iowa Caucus

Prediction: Cruz Wins Iowa Caucus
Based on the latest poll data, it is likely that Cruz will win the most delegates in Iowa. The current estimate of the popular vote among caucus-goers is Cruz: 30%, Trump 22%, Rubio 14%, with remaining candidates' support being too small to be certain. The 95% confidence is +/- 8%, representing the high uncertainty of this type of race.

There are three key factors that I am considering:
1) The result of a couple of polls with high quality samples, which come close to the exit poll demographics from 2008 and 2012 (Fox News and NBC/WSJ/Marist)
2) The data from a PPP poll, giving some insight into the second preferences of voters
3) An examination of past behavior of Iowa caucuses

One important factor to keep in mind is that approximately half of the people who attended the caucuses in 2008 and 2012 did not make up their mind until the last month, with about a quarter deciding in the last week or less. This is supported by the polls that I can see from those times. This doesn't mean that they had no idea who to support, or that they wouldn't end up going with their best guess from December. However, it does mean that the majority of voters' preferences are still fluid, and they could easily change their mind to a second choice.

This is important as we look at a number of candidates at the back of the pack, who may be seeing falling numbers. As certain candidates seem less viable, a snowball effect takes place, where falling support makes voters who are leaning towards that candidate to re-evaluate their position. The very nature of the caucus amplifies this effect, as an uncertain voter walks into a person's home or other small gathering on caucus day, and finds that they are pretty much alone in their support for candidate A.

So where are these fluid votes going to flow? For any candidate looking at less than 5% of the vote, the second choice is for Cruz over Trump, at more than 2:1. Particularly noteworthy is Paul supporters, who are know to be well organized and well placed for the caucuses, who favor Cruz 5:1 over Trump (but with almost equal preference for Carson).

Another interesting point is that while voters who lean towards Trump are still considering Cruz as a second choice (36%, far above any other candidate), Cruz supporters are much more likely to support Rubio than Trump (26% to 18%). Similarly, 36% of Carson supporters see Cruz as a second choice, versus 12% considering Trump. The bad news for Rubio is that, other that Cruz supporters, almost no one else sees him as a good second choice (including Bush supporters).

The take home message on this is that in the midst of a chaotic field, any volatility aims to favor Cruz.