Non-market economy determination in anti-dumping law permits rebuttal and market-based treatment for qualifying firms. Amendment sets a rebuttable presumption that a country treated as a non-market economy within the prior three years is such for anti-dumping purposes, but allows the country or its firms to rebut this by demonstrating, against specified criteria, that prices, costs, inputs and investment respond to market signals without significant state interference, that production costs are not distorted by legacy non-market practices, that bankruptcy and property laws ensure legal certainty, and that exchange rate conversions are carried out at market rates; where firms meet these criteria, market-based principles may be applied.