Mantic Monday 5/9/22

https://astralcodexten.substack.com/p/mantic-monday-5922

Changes in Ukraine prediction markets since my last post April 18:

1. Will at least three of six big cities fall by June 1?: 5% → 2%

2. Will World War III happen before 2050?: 22% →25%

3. Will Russia invade any other country in 2022?: 5% →10%

4. Will Putin still be president of Russia next February?: 85% → 80%

5. Peace or cease-fire before 2023?: 65% → 52%

6. Will Russia formally declare war on Ukraine before August?: (new) → 19%

IE predicting the results of the recent Supreme Court link.

Quick summary: markets already expected that the Court would overturn Roe v. Wade (~70% soon), but this moved them closer to 95% immediately. Democrats’ chances in the mid-terms went up 3-5% on the news. Markets are extremely skeptical of claims that this will lead to bans on gay marriage or interracial marriage, or that the Democrats will respond with (successful) court-packing. A single very small and unreliable market says the leak probably came from the left, not the right.

Going through at greater length one-by-one:

First: how much did the leak change predictions about the case itself? PredictIt had a market going, which said that even before the leak there was only a 15% chance the Court would make Mississippi allow abortions; after the leak, that dropped to 4%.