This will be a brief blog entry but it does not need to be lengthy. As far I can tell the first person to postulate and go into detail about how the divine economy operates at the level of the individual was Sant' Antonio of Florence (1389-1459).
Sant' Antonio was a significant contributor to economic theory along with the other contributors during the Late Scholastic period. He took the abstract principles of theology and ethics and applied them to the detailed empirical data of daily life.
It is an honor to revive such a meaningful postulate. Unnamed before, this theoretical effort is now referred to as divine microeconomy theory!