SO BEGINS Donald Trump’s tariff roller-coaster, certain to be a stomach-churning experience for the worldwide economic system. He began his first day in office with an sudden present of restraint: somewhat than slapping hefty new tariffs on other countries, he as a substitute issued a presidential memorandum calling for a evaluation of unfair commerce practices. It appeared to be a measured begin for Mr Trump—a minimum of on the protectionist entrance, if not his wider programme—prompting reduction in authorities places of work and on buying and selling flooring around the globe. Foreign exchange and shares rallied.