In “End of inflation in the kingdom of Lizarb” —where “everything is back to front” —he skewered the belief that rising prices cause fiscal deficits.
Some doubt that Mr Bacha merits immortalisation.
Novelists and poets on the academy argued that most of his dozen books are dry treatises.
His liberal economics is anathema to humanists enamoured of Karl Marx.
Still, he beat Eros Grau, a former supreme court justice (who has written erotic fiction).
The unusually close vote (of 18 to 15) exposed a rift between the academy's “culture wing” and its clutch of public servants, including two former presidents.
In November a contest between a political scientist and a philosopher-poet ended in an unprecedented tie, forcing a new election with fresh candidates.
Joo Almino, a writer and diplomat, got the open seat.
Mr Bacha's elevation may be a sign that economic liberalism is regaining ground.
In March street protesters called for privatisation and deregulation, among other things.
The government of Michel Temer may prove to be one of the most liberal that Brazil has ever had.
The academy is also becoming harder-headed.
Some immortals were reportedly keen to elect a former banker to oversee its investments.