You are hereby forbidden from talking about the Dow ever again. The S&P 500 weights 500 constituents by their market cap; the Dow weights 30 random-ish constituents by their PRICE. IBM's weight in the Dow is 4.5 times that of GE because it had a couple fewer stock splits over the years or issued fewer shares; in the S&P its weight is, correctly, about 60% of GE's, because it's a smaller company. The Dow is what crazy people talk about on CNBC.
Also, Intrade should list the conditional futures---S&P price with bailout, S&P without bailout.
With today's snapback, the Dow lost 777 and regained 485.
As of this evening, Intrade says the probability of a bailout bill passing by Oct 31st is 85%.
(777-485)/(1-.85) = 1,946. So a bailout bill makes an expected difference of 2000 points on the Dow.
Of course this is a bogus calculation, but it's an interesting one. Not overwhelmingly on-topic for OB, but it involves prediction markets and I didn't see anyone else pointing it out. I hope the bailout fails decisively, so this calculation can be tested.
PS: Bryan Caplan understands Bayes's Rule: It's not possible for both A and ~A to be evidence in favor of B. So which of the two possibilities, "unemployment stays under 8% following a bailout" and "unemployment goes over 8% following a bailout", is evidence for the proposition "the bailout was necessary to prevent economic catastrophe", and which is evidence against? Take your stand now; afterward is too late for us to trust your reasoning.