A consideration in quantifying the impact of a trade measure on carbon-intensive industry in the United States is whether the relevant market is at home or abroad.

Demand for steel in industrialized countries has, in fact, declined over the past 15 years, while demand from the developing world has tripled. Demand for aluminum, paper, and chemicals has grown in industrialized countries but has still been far outpaced by demand from emerging economies. China, which alone has accounted for three-quarters of the growth in global steel, cement, and aluminum production over the past decade, has built out capacity primarily to supply its fast-growing domestic market.

While overcapacity has made China the world’s largest steel exporter, only 8 percent of total production was sold abroad in 2005 and less than 1 percent showed up in the United States.