Does the mathematics of the prediction (in terms of the joint wave function) give the information, or do you mean the information stems from the measurement at one detector? I can see the joint probabilities for both electrons as being predictive, but when we talk about specific measured states, none of that is predictive is it? I appreciate that the measured state is kind of book keeping, but I still find it difficult to relate this book keeping as being common to two separated locations. I mean I cannot predict from the joint wave function that an entangled particle at source will evolve to have a specific measured up state at detector A and a specific measured down state at detector B can I? All I can say is that there is a 50% chance of it being up or down in either location and that the rules say if it is up in one detector it will be down in the other. Are you saying that the book keeping is just recording the nature of the predictive outcome, it is just the final part of the quantum prediction that gives a chance to tabulate the probability outcomes - the measurement should not be thought of as some kind of deterministic event that kicks in to ensure the other particle follows the rules, but rather the rules are inherent in the wave function which is a product of our experimental set up.

I don't wish go back over ground that was amply covered in the thread ("Spooky Matter at a Distance" - in General Science I think) but it seems like an opportunity to clarify a few points.