Donald Trump’s method of calculating which countries get hit with “reciprocal” tariffs has stunned financial markets and baffled trade experts, who say the methodology would not pass a basic economics exam.

For the past two months, the president has warned that his most senior officials were carrying out an in-depth analysis of the tariffs and non-tariff barriers — such as regulations and taxes — applied by other countries on the United States to calculate the level of “reciprocal” measures the administration would announce this week.

Instead, what emerged from Trump’s Rose Garden announcement that upended the global economic order was a rule-of-thumb estimate economists say has little bearing on real trade barriers or bugbears such as VAT or tech taxes in Europe, which Trump has