I don't understand "explanatory is a subset of relevant". If it does not (partially or not) explain the observed result, how can you decide whether it is releva

I don't understand "explanatory is a subset of relevant". If it does not (partially or not) explain the observed result, how can you decide whether it is relevant ? As for the other links, I don't see numbers related to PPP, but maybe I misunderstand those graphs (I don't understand income per unit of consumption). I also don't see how he can deduce the difference is coming from gvt differences. I am only familiar with statistics, so I may be missing the subtlety of a field I am unfamiliar with (economy), but those analysis seem quite superficial to me. Certainly, they don't warrant such strong conclusions.