Mr. Trump’s tariffs would raise the prices of imported goods sharply, cutting the purchasing power of every American. Lower-income Americans — including Mr. Trump’s core supporters — would be hurt the most because they disproportionately buy less expensive imported items. For China, and particularly Mexico, the economic costs would be significant, which is why at one point on Wednesday the Mexican peso had plunged by more than 13 percent.

While some manufacturing jobs might come back as a result of the tariffs, a greater number of domestic jobs would most likely be lost because Americans would have less spending power. A recent study by the nonpartisan Peterson Institute for International Economics estimated that, rather than bringing jobs back to the United States, Mr. Trump’s tariffs could result in a trade war that would cost our economy five million jobs and possibly lead to a recession.

The centerpiece of Mr. Trump’s plan is a huge $5.8 trillion tax cut unaccompanied by specificity around what expenses would be cut to pay for it. (Indeed, the president-elect has proposed more spending on defense and infrastructure.)

As soon as Mr. Trump’s ascendancy became clear on Tuesday night, interest rates on Treasuries began to rise. Usually, an unexpected event causes a flight to the safety of government debt, pushing yields down. That the opposite occurred reflects fears that the deficit might balloon out of control.