SANTIAGO, CHILE — Sebastián Piñera, a political conservative, returned to Chile’s presidency on Sunday, vowing to revive an economy that slumped under the departing center-left leader Michelle Bachelet.
Ms. Bachelet handed the presidential sash to the president of Congress, who then swore in Mr. Piñera — who himself turned over the office to Ms. Bachelet in a similar ceremony four years ago.
Mr. Piñera, a billionaire entrepreneur, oversaw growth that averaged 5.3 percent a year during his first term from 2010 to 2014, aided by pro-business policies, rising prices for Chile’s chief export, copper, and a giant rebuilding effort following a magnitude 8.8 earthquake that hit just before he took office.
A slump in copper prices helped sour Ms. Bachelet’s second round as president, with the economy — and the president’s popularity — slipping badly in 2014 and 2015. Ms. Bachelet, the first women to lead the country, had been wildly popular when she ended her initial term and handed power to Mr. Piñera.
“From Day 1, Piñera is going to want to show that under him, the wheels of the economy will start to spin again,” said Cristóbal Bellolio, a professor of government at the Adolfo Ibáñez University.
Mr. Piñera’s first administration was marked by major street demonstrations demanding reforms in education and other services, as well as by the start of softening copper prices. He left office with favorability ratings in the 30s.