President-elect Donald Trump claims he can unilaterally impose sweeping tariffs on U.S. imports. The reality is more complicated, according to trade experts.

The calculus for tariffs has always been far more complicated than their effect on consumer prices — and even that is not perfectly understood.

An analysis by the nonpartisan Peterson Institute for International Economics estimates Trump’s proposed tariffs would cost a typical U.S. household more than $2,600 a year. “High tariffs also imply a massive shifting of the tax burden from richer taxpayers toward lower-income Americans,” the report said.