latest Betfair odds

[emailking]

Sanders has the highest implied odds in the general election, 64.5%.

Huh?

Winning individual odds / primary odds

That only works if the market is efficient - which it clearly isn't, as the individual Democrats' chances of winning the WH add up to more than the Democratic Party's chances of winning the WH.

Well there aren't any actual odds here in a scientific sense, even if the market is efficient, as it's a non-repeatable event whose result we can only guess at in a Bayesian sense. Also I imagine there are many people betting that don't even understand that the odds have to add up like that (much less consciously considering that when betting), adding a further wrinkle as to how they should be interpreted. So I think his metric is as good as any basically, given the data there is to go on.

[Absentee Voting Ghost of Ruin]

Sanders has the highest implied odds in the general election, 64.5%.

Huh?

Winning individual odds / primary odds

That only works if the market is efficient - which it clearly isn't, as the individual Democrats' chances of winning the WH add up to more than the Democratic Party's chances of winning the WH.

Do they not allow short selling?

They might. Go make some money if they do (or not, from your state icon - Betfair is illegal for Americans).

PredictIt allows short selling, and is roughly as legal for Americans as the Iowa Electronic Market.

[Mr. Morden]

Like I said earlier, the numbers I'm posting are "Betfair Exchange" numbers, which AFAIK works pretty much like the old Intrade did, in that every transaction is by definition a trade between who's buying an event and someone else who's short selling the same event.  This is in contrast to the vanilla version of Betfair, where the price is set by bookies.

So no, short selling isn't disallowed.  It's *required* that every trade involves someone short selling, to counteract the person buying.

That said, you're right that the volume doesn't tend to be high enough to make the market perfectly efficient.  On the "winning individual" market, a given candidate might go several days without having any shares traded.  Thus winning individual is more likely to lag in certain trends as compared to the nomination markets.

[Sprouts Farmers Market ✘]

Not Betfair, but on PredictIt, Bush is down 7 cents and Christie is up 8 cents. I'll let Morden give the other side of this

Average of Buy/Sell Yes Shares
Rubio 46
Cruz 21.5
Trump 21 (22 on the buy-side which was the last transaction
Bush 23 (21 on the sell-side, which was the last transaction. Very wide spread)
Christie 14.5
Kasich 14.5
Carson 14.5 (13 on the sell-side which was last transaction)
Paul 7.5
Jindal 6
Santorum 5 (weird last transaction)
Huckabee 4.5 (last transaction at 6)
Fiorina 8 (last transaction at 5 on sell-side; down 8 cents)
Graham 4
Pataki 2.5

[Mr. Morden]

Rubio’s soaring and Bush is getting killed in the markets tonight.  Trump again passes Bush to take second place for the nomination, and he’s also now ahead of Bush in winning individual.

Fiorina’s at her lowest point since Sept. 2nd and I think Bush is at his lowest point in more than a year, back when there were still big doubts about whether he’d actually run.

Up: Clinton, Rubio
Down: Bush, Fiorina

Democrats
Clinton 87.7
Sanders 13.8

Republicans
Rubio 38.0
Trump 18.3
Bush 15.4
Carson 10.9
Cruz 7.5
Christie 4.2
Fiorina 4.0
Huckabee 3.1
Kasich 2.6
Romney 1.1

Winning Individual
Clinton 54.1
Rubio 16.8
Sanders 9.1
Trump 7.5
Bush 5.7
Carson 4.2

[I spent the winter writing songs about getting better]

Bush is still way overvalued.

[TarHeelDem]

We have reached a point where Donald Trump has a better chance of being our next president than Jeb Bush. I dislike Jeb Bush, but God in Heaven, what is this nation coming to?

[Craigo]

Sanders has the highest implied odds in the general election, 64.5%.

Huh?

Winning individual odds / primary odds

That only works if the market is efficient - which it clearly isn't, as the individual Democrats' chances of winning the WH add up to more than the Democratic Party's chances of winning the WH.

Well there aren't any actual odds here in a scientific sense, even if the market is efficient, as it's a non-repeatable event whose result we can only guess at in a Bayesian sense. Also I imagine there are many people betting that don't even understand that the odds have to add up like that (much less consciously considering that when betting), adding a further wrinkle as to how they should be interpreted. So I think his metric is as good as any basically, given the data there is to go on.

I agree with everything but the bolded sentence. Bad methodology doesn't magically become good just because a better method is not currently practicable. His method is probably the best that you can do with this data without some hardcore math that I left behind in grad school, and I don't blame anyone for wanting to divine that information - but it's still not good. We just don't have the data needed to answer that question with any confidence.

[Craigo]

Like I said earlier, the numbers I'm posting are "Betfair Exchange" numbers, which AFAIK works pretty much like the old Intrade did, in that every transaction is by definition a trade between who's buying an event and someone else who's short selling the same event.  This is in contrast to the vanilla version of Betfair, where the price is set by bookies.

So no, short selling isn't disallowed.  It's *required* that every trade involves someone short selling, to counteract the person buying.

That said, you're right that the volume doesn't tend to be high enough to make the market perfectly efficient.  On the "winning individual" market, a given candidate might go several days without having any shares traded.  Thus winning individual is more likely to lag in certain trends as compared to the nomination markets.

Thanks for that info. I didn't know the volume numbers, good to know.

[eric82oslo]

Republicans
Huckabee 3.1
Kasich 2.6

I would have expected Kasich to be ahead of Huckabee at this point.

[Eraserhead]

We have reached a point where Donald Trump has a better chance of being our next president than Jeb Bush. I dislike Jeb Bush, but God in Heaven, what is this nation coming to?

Trump would be a much better President than Bush would.

[eric82oslo]

We have reached a point where Donald Trump has a better chance of being our next president than Jeb Bush. I dislike Jeb Bush, but God in Heaven, what is this nation coming to?

Trump would be a much better President than Bush would.

False statement. Your pants are on fire. Unless you consider the US government turning into a terrorist organisation where it breaks up the lives of 11 million families and absolutely destroys them morally, financially, psychologically and in every other way imaginable as being a decent presidency. If that's the case, then maybe you're right. I however, would never call widespread terror at that level for anything inherently good. Kasich is right about that. Maybe because he's a decent guy with his family values still intact.

[Mr. Morden]

And a few hours later, the Bush crash has gotten so bad that he’s now only tied for third with Carson:

Up: Christie
Down: Bush

Rubio 38.5
Trump 18.3
Bush 11.4
Carson 11.4
Cruz 7.8
Christie 5.3
Fiorina 4.0
Huckabee 3.1
Kasich 2.9
Romney 1.3

[emailking]

I agree with everything but the bolded sentence. Bad methodology doesn't magically become good just because a better method is not currently practicable. His method is probably the best that you can do with this data without some hardcore math that I left behind in grad school

Are you saying you think there's a way to use both the Democrats' chances of winning the White House and Sanders's winning individual odds to assess his implied odds of winning the general? Like a weighted average or something?

[muon2]

I agree with everything but the bolded sentence. Bad methodology doesn't magically become good just because a better method is not currently practicable. His method is probably the best that you can do with this data without some hardcore math that I left behind in grad school

Are you saying you think there's a way to use both the Democrats' chances of winning the White House and Sanders's winning individual odds to assess his implied odds of winning the general? Like a weighted average or something?

The math is pretty straightforward if we assume that the probability of a generic D vs R is independent of the particular candidate. Certainly the candidate matters, but long term the mood of the electorate towards a particular party probably matters more. So, I'll make that assumption to simplify the math for the first part.

If the candidate selection in the primary is independent of the general election then the probability of an individual winning the general election is the product of their probability of winning the nomination times the probability that their party wins the general election. For example if Clinton has an 80% chance of winning the nomination and the Dems have a 60% chance of winning the general election, then Clinton would have a 48% chance of winning the general election as an individual (0.80*0.60=0.48).

Given both the probability of individuals winning the primary and general election I can flip the equation around and solve for the probability that their party wins the general election. So given Clinton at 87.7% to nominate and 54.1% to elect, that means the expectation is that the Dems win 61.7% in the general. For Sanders at 13.8% to nominate and 9.1% to elect the expectation is that the Dems win 65.9% in the general. Hence the claim that Sanders is placed to fare better than Clinton in the general election. Of course the probabilities are not independent so there is no expectation that the results would be identical.

More likely the effect is due to the traders themselves. As a contract gets lower there's more perceived upside relative to the risk. This could lead a trader to overvalue a Sanders contract to win the general election with respect to a Clinton contract. The general election contracts are lower than the primary contracts due to the co-mingling of both parties so the effect is compounded for Sanders compared to Clinton. The net effect is that Sanders appears to be more likely than Clinton to win the general in the minds of the Betfair traders.

[Mr. Morden]

Bush and Carson both drop.  Bush again alone in 3rd place, but it’s close.

Democrats
Clinton 87.7
Sanders 13.4

Republicans
Rubio 38.0
Trump 18.0
Bush 10.0
Carson 9.5
Cruz 7.8
Christie 5.3
Fiorina 3.6
Huckabee 2.9
Kasich 2.6
Romney 1.3

Four years ago at about this time on Intrade:

https://uselectionatlas.org/FORUM/index.php?topic=93015.msg3072308#msg3072308

You must be logged in to read this quote.

Eight years ago at about this time on Intrade:

https://uselectionatlas.org/FORUM/index.php?topic=50282.msg1327463#msg1327463

You must be logged in to read this quote.

[eric82oslo]

Kasich still being below Huckabee is just mindboggingly laughable and ridiculous. >

I loved Huckabee in 2008, cause back then he was the closest thing we had to Trump - an entertainment figure - as well as to Carson - really funny at times. Yet during this campaign Huckabee has shown to be at the very most extremes 20-25% of his former self. Usually he's only hoovered in the 12-15% range though. At the same time Kasich has had two out of three hands down absolutely amazing debates. I admit that he sucked almost as horrifically as Trump at the second debate, yet his first and third debates were both absolutely world class. Huckabee during this season so far has had two extremely, on the brink of laughably, bad performances, plus one below mediocre. And still the pundits pretend like Huckabee still has a better chance than Kasich?!? Are they on medical marijuana or something?

[bobloblaw]

Bush in danger of falling below Carson....tee hee

[Mr. Morden]

Rubio hits 40.  Carson moves back up into a tie with Bush for 3rd place.

Up: Rubio, Cruz
Down: Trump, Christie

Democrats
Clinton 87.7
Sanders 13.4

Republicans
Rubio 40.0
Trump 16.8
Bush 10.0
Carson 10.0
Cruz 9.1
Christie 4.3
Huckabee 3.6
Fiorina 3.1
Kasich 2.3
Graham 1.1

Winning Individual
Clinton 56.8
Rubio 18.0
Sanders 8.4
Trump 6.8
Bush 5.0

[Torie]

So the markets think that Jeb! will be the strongest Pub candidate in the General election. Fancy that! Yes, Muon2 has made a rather more nuanced comment about this, but I just wanted to share. Jeb! needs good news about something.

[Eraserhead]

Rubio and Carson are too high. Trump and Cruz are too low.

[Torie]

Rubio and Carson are too high. Trump and Cruz are too low.

Carson's unorthodoxy is a loser, while Trump's is a winner, in other words. Got it.

[Mr. Morden]

Bush has a slight rebound, and Cruz passes Carson for 4th place.

Up: Bush, Christie
Down: Rubio

Democrats
Clinton 88.5
Sanders 12.5

Republicans
Rubio 38.0
Trump 17.4
Bush 11.1
Cruz 9.5
Carson 9.1
Christie 5.3
Huckabee 3.6
Fiorina 2.9
Kasich 2.4
Graham 1.1

Four years ago at about this time on Intrade:

https://uselectionatlas.org/FORUM/index.php?topic=93015.msg3074207#msg3074207

You must be logged in to read this quote.

Eight years ago at about this time on Intrade:

https://uselectionatlas.org/FORUM/index.php?topic=50282.msg1328829#msg1328829

You must be logged in to read this quote.

[Lyin' Steve]

Hillary + Sanders is 101, is there a reason why you can't just sell both of them and be guaranteed a 1% profit?

[Lyin' Steve]

By the way, I love from the beginning of this thread, one of the odds posts:

64. Donald Trump - 126
74. Ben Carson/Karl Rove/George Clooney - 201