Ambassador Katherine Tai, the United States trade representative, said the world economy needs to evolve in order to solve global problems like climate change and the COVID-19 pandemic. In an interview with “Marketplace” host Kai Ryssdal, Tai said we need to reimagine incentives to stop the “race to the bottom.” “We don’t exist in a vacuum,” Tai said. “These are collective challenges, and we only get through them if we can get through it collectively.” Also on today’s show: President Joe Biden said a “whole of government” approach is needed to fight climate change, why home construction costs exploded in the last year, and the USDA is extending its free lunch program.