not be strongly impacted, at least in the medium to long run. He believes that the US should not repeat Reagan's 1981 policy on taxes and quotas on imported products, as even if it does not produce a recession, protectionism would shock "value chains" and disrupt jobs and communities in the same way as free trade in the past. In addition, other countries would take retaliatory measures against US exports. Krugman recommended against the abandonment of NAFTA, because it could cause economic losses and disruptions to businesses, jobs, and communities. In the late 2010s, Krugman admitted that the models that scholars used to measure the impact of globalization in the 1990s underestimated the effect on jobs and inequality in developed countries such as the US. He noted that although free trade has harmed some industries, communities, and some workers, it remains a win-win system overall, enriching both parties to the agreement at the national level; a trade war is equivalently negative for the nations involved, even while it may benefit some individuals or industries within each nation. Immigration Krugman wrote in March 2006: "Immigration reduces the wages of domestic workers who compete with immigrants. That's just supply and demand: we’re talking about large increases in the number of low-skill workers relative to other inputs into production, so it's inevitable that this means a fall in wages ... the fiscal burden of low-wage immigrants is also pretty clear." Green economy Krugman has called for a transition to a green economy. He supported the Green New Deal., asserting "I believe progressives should enthusiastically embrace the G.N.D.". He said that a "Green New Deal stuff is investment. On that stuff, don’t worry about paying for it. Debt as an issue is vastly overstated, and a lot of these things pay for themselves. Go ahead and just deficit finance it." In 2021, he wrote that "we will almost surely have to put a price" on greenhouse gas emissions. He criticized Democratic "moderates" and corporations "torpedoing efforts to avoid a civilization-threatening crisis because you want to hold down your tax bill". Political views Krugman describes himself as liberal, and has explained that he views the term "liberal" in the American context to mean "more or less what social democratic means in Europe". In a 2009 Newsweek article, Evan Thomas described Krugman as having "all the credentials of a ranking member of the East coast liberal