Final answer:
'Moneyball' was popularized by the book 'Moneyball: The Art of Winning an Unfair Game', with Billy Beane credited with the concept and he was the general manager of the Oakland Athletics at the time.
Step-by-step explanation:
The provided reference information does not contain details regarding the invention of 'Moneyball'. The question seems to be asking about a specific concept within baseball history related to team management and economics, namely 'Moneyball'. To directly answer the student's question, 'Moneyball' is a term popularized by Michael Lewis's 2003 book 'Moneyball: The Art of Winning an Unfair Game', which discusses how the Oakland Athletics baseball team and its general manager, Billy Beane, used statistical analysis (sabermetrics) to assemble a competitive team despite the franchise's limited budget. Therefore, the person credited with inventing the 'Moneyball' concept is Billy Beane, and he was the general manager of the Oakland Athletics at the time the concept was implemented and gained notoriety.