Milei, who is pledging economic shock therapy such as shutting the central bank and dollarization, won a second-round runoff vote on Sunday with some 56% to rival Sergio Massa's 44%.
Milei now faces the huge challenge of turning around the economy once he takes office on Dec. 10.
"It is an economy that is in intensive care," said Miguel Kiguel, a former undersecretary of finance at the Economy Ministry in the 1990s.
A central bank poll of analysts forecast 185% inflation by the end of the year.
In a bid to tamp down inflation Argentina's central bank has hiked the benchmark interest rate to 133%, which encourages saving in pesos, but hurts access to credit and economic growth.
Persons:
Javier Milei, Sergio Massa's, Milei, Miguel Kiguel, Lucio Garay Mendez, Vaca Muerta, Eugenio Marí, Hernan Nessi, Adam Jourdan, Daniel Wallis, Chris Reese
Organizations:
Economy Ministry, Reuters Graphics Reuters, Coldplay, Reuters Graphics, CENTRAL, International Monetary Fund, Libertad y Progreso Foundation, Thomson
Locations:
BUENOS AIRES, dollarization, Argentina, China, Brazil