PPA 9: Putting it All Together

[This is the ninth piece in my series on the Parametric Process Assumption (PPA), a new model of anthropics. You should start here if you only want to read one piece on the PPA, but if you only want to read two pieces, this is the second one to read. The previous piece is " The Fermi Paradox, Fine-Tuning, and the SSA ." TLDR: The SSA's bias for Doomsday only applies if your reference class only includes your own species. The more more species in your universe/reference class, the less Doomsday effect you see The Basic Model of anthropics models the universe as a process progressing randomly until certain relevant subprocesses emerge spontaneously. An intelligent species like humans would be an example of one such process. It has 3 components: (Epistemic) Propensity for Life: How many times does an observer-creating process emerge, on average? (Aleatoric) Longevity: For each emergence, how many observers does the process produce before it terminates? Diversity : Everything else. When a process starts, what do the observers experience? What do they look like? etc. The previous arguments in this series tell us many things about the Basic Model Diversity has no effect on the SSA, SIA or PPA The SIA acts as an improper prior over longevity but not propensity The SIA gives an undue bias towards large propensity The PPA treats propensity as an epistemic parameter and longevity as aleatoric, avoiding both Doomsday and presumptuousness The next piece, " Deriving the PPA ," begins the…