Hi there. I found a paper ( http://users.ox.ac.uk/~lina0174/born.pdf ) which states that has derived the Born Rule. More or less, what I understood is that: 1) Consistency condition: if we are going to represent an experiment through different, but coherent representations (ie, different Hilbert basis of the same situation), then, the probabilities that we deduce from whatever rule we will invent from these representations should be the same. 2) Consequence: The probabilities should be calculated from the born rule. What do you think about this first papers? Related to this topic, I found another paper from David Deutsch (which I found less appealing, but there seems to be a lot of people developing this line of thought since 1999) in this link ( http://xxx.lanl.gov/ftp/quant-ph/papers/9906/9906015.pdf ). In this paper, it seems like they derive the Born Rule assuming rationality of the "agents" taking ideas from decision theory???. As I said I found this other paper much less appealing to me than the first one, but: 1) To be appealing or not is a matter of taste 2) There are a lot of other papers, developed in the last 10 years, that tried to continue this line of thought. So, What do you think about this second paper?