A literature review conducted by the OECD finds that there is robust evidence that open economies are richer and more productive than closed economies and that the studies that most convincingly establish this link find that an increase in the share of trade in GDP of one percentage point raises the income level by between 0.9% and 3% (Nordas et al., Irwin (2002) concludes that despite shortcomings in method and measurement, cross-country studies of growth suggest that economies with more open trade policies tend to perform better than those with more restrictive trade policies. He cites historical experience from South Korea, which liberalised its trade policies in the 1960s, Chile, which liberalised in the 1970s, and India, which liberalised in the 1990s. The steady reduction in trade barriers, particularly in manufactured goods, has enabled them to rapidly integrate into world markets through an export-led industrialisation processes.