I'm currently conducting an experiment on PRMs. It'll take me a season to have some tangible results. Basically I'm keeping track of my economic situation each week (attendance & merchandising). For now my PRM is a lvl 2 with National Appeal spec. I plan on buying a lvl 4 same spec. in 3 weeks (so I'll have 6 weeks of records for each PRM). I guess I'll also have to take into account my results throughout the season (such as TV games, rivalry games, W/L etc...). I hope it'll shed some light on the matter of direct influence of PRMs on merch.
PS : the big bang theory is one of many scientific theories that tries to explain what happened just after time 0, it's impossible to determine what happened precisely at time 0... So god is not a stupid explanation, it's possible. It depends on how you define god.