The world collapse, MC succed to survive and spend these days with a trader, ok great ! But ... Where does someone who probably does not have a lot of knowledge in Economics end up making sheets representative of future events ?
Certainly MC comes to us from the future, certainly he spent time in the company of Jonathan ... But at most this comrade-in-arms only transmitted bits of information to him about what he, Jonathan, experienced ! After all, MC's journey was to be part of the military, maybe he was a genius, but without being hooked on the economy of the years of the disaster, he normally had no way of knowing all !