The Moscow vs. New York example illustrates the difficulty with comparing worlds that are not different hypotheses about how the same world could be, but two distinct objects.
There doesn’t seem to be a problem here. The comparison resolves to something along the lines of:
Consider all hypotheses about the physical world of the present time which include the object “Moscow”.
Based on all the information you have calculate the probability that any one of those is the correct hypothesis.
Do the same with “New York”.
Compare those two numbers.
???
Profit.
Instantiate ”???” with absurdly contrived bets with Omega as necessary. Rely on the same instantiation to a specific contrived decision to be made to resolve any philosophical issues along the lines of “What does probability mean anyway?” and “What is ‘exist’?”.
What you describe is the interpretation that does make sense. You are looking at properties of possible ways that the single “real world” could be. But if you don’t look at this question specifically in the context of the real world (the single fact possibilities for whose properties you are considering), then Moscow as an abstract idea would have as much strength as Mordor, and “probability of Moscow” in Middle-earth would be comparatively pretty low.
(Probability then characterizes how properties fit into worlds, not how properties in themselves compare to each other, or how worlds compare to each other.)
There doesn’t seem to be a problem here. The comparison resolves to something along the lines of:
Consider all hypotheses about the physical world of the present time which include the object “Moscow”.
Based on all the information you have calculate the probability that any one of those is the correct hypothesis.
Do the same with “New York”.
Compare those two numbers.
???
Profit.
Instantiate ”???” with absurdly contrived bets with Omega as necessary. Rely on the same instantiation to a specific contrived decision to be made to resolve any philosophical issues along the lines of “What does probability mean anyway?” and “What is ‘exist’?”.
What you describe is the interpretation that does make sense. You are looking at properties of possible ways that the single “real world” could be. But if you don’t look at this question specifically in the context of the real world (the single fact possibilities for whose properties you are considering), then Moscow as an abstract idea would have as much strength as Mordor, and “probability of Moscow” in Middle-earth would be comparatively pretty low.
(Probability then characterizes how properties fit into worlds, not how properties in themselves compare to each other, or how worlds compare to each other.)