According to the Internet, according to the Washington Post, after Trump took office as president of the United States, the government's economic staff began a difficult task: setting tariff rates for dozens of countries to fulfill his campaign promise of setting up "reciprocal" trade barriers. After weeks of work, aides from several government agencies have developed a list of options covering a variety of trade practices. However, Trump himself chose a formula based on two simple variables. Sources said it was unclear who proposed the option, but it had some striking similarities to the approach published by Navarro, a tough economic adviser during Trump's first administration. Markets fell sharply on Wednesday after the tariff measures were announced, a crude calculation that was ridiculed by economists. The report also said that after discussions late Tuesday night, Trump did not decide on his final plan until around 1 p.m. Wednesday-less than three hours before his announcement in the Rose Garden.