Mark Carney, who has never held elected office but has a long résumé in economic policymaking and investing, was sworn in Friday morning as Canada’s 24th prime minister. He will have no time to ease into his role. Canada is…

Mark Carney, who has never held elected office but has a long résumé in economic policymaking and investing, was sworn in Friday morning as Canada’s 24th prime minister. He will have no time to ease into his role. Canada is…