MARK CARNEY made his name as a sound steward of money. He entered the public eye in 2008 when he was appointed governor of the Bank of Canada at the age of just 42, and his swift and decisive interventions there are credited with helping the country weather the storm of the global financial crisis better than any other rich nation. From 2011 to 2018, he was chair of the global Financial Stability Board, established in the wake of that crisis to strengthen oversight of the world’s banks and try to avoid a repeat. In 2013, Carney was appointed governor…