The article looks at how the U.S. made trade policies during the Smoot-Hawley tariff in 1930. They studied how tariffs were decided based on lobbying by companies and workers, as well as trade terms. By analyzing data from 1927-35, they found that most tariffs were influenced by company lobbying, but some were also based on trade terms. In 1931, workers pushed for more protection in the Smoot-Hawley tariff.