In Could Donald Trump Drop Out? Some Bettors Seem to Think So, Justin Wolfers extrapolates the probability that Donald Trump will quit the US presidential election, based on betting markets. The basic facts he uses are that Betfair has 25.8% odds of the Republican Party winning the 2016 election, but a 24.1% chance of Trump doing so.
Wolfers asks “what are the odds he quits?”
However, Donald Trump quitting is not the only way that another Republican wins the presidency.
Particularly, any of these are possibilities:
- Trump could be forced out by the party
- Trump could die of natural causes (he is 70, after all)
- Trump could be assassinated
The election is three months away, and a lot can happen.
I don’t think any of these are likely things, nor do I want Trump to die (and I’m certainly not encouraging anyone to attempt to make that happen). But we’re talking about splitting up a small probability to begin with.
Remember, these aren’t necessarily correct probabilities. Instead they represent beliefs (which should correlate with true probabilities). As long as some small percentage of people think there is a decent chance of Trump being assassinated, then a non-negligible part of that 1.7% will be due to assassination beliefs, not quitting beliefs.
If the Republican chances of victory vary by the circumstances in which Trump is not their candidate, then all of the math further down in the Upshot article needs further adjustment. Especially if the alternative Republican is more likely to win if Trump is assassinated than if Trump quits, then a bigger chunk of that 1.7% belongs to that case than simply the relative likelihood of assassination vis-a-vis the other circumstances.
Even if your opinion is that this is highly unlikely (or a distasteful thing to bet on), that doesn’t mean that others feel the same way. It should have been acknowledged in the article.
How likely do YOU think it is that Trump quits?