It&#x27;s not clear to me how (and if) Occam&#x27;s Razor should necessarily be applied in this context. We are not choosing between a very simple, and a vastly complex alternative. Rather we are choosing between an unintuitive and probably complex option (contraceptives are causing less copulation - this does not sound at all like a simple suggestion to me), and admitting that our models and data may not be complete. Either way we need more research to be able to more clearly identify the root causes.