This paper by Thomas Hatzichronoglou, published in the OECD Directorate for Science, Technology and Industry's Working Papers series, discusses the methods used to classify OECD countries' industrial sectors and manufactures by level of technology. The paper presents two new classifications: one by industrial sector and one by product. The sectoral classification identifies four groups of industries based on technology intensity, considering both the level of technology-specific R&D expenditure and the technology embodied in intermediate and capital goods. The product classification focuses solely on high-technology products, which are the most technology-intensive. The sectoral classification is based on the International Standard Industrial Classification (ISIC Rev. 2) and covers manufacturing industry. The product classification is based on the Standard International Trade Classification (SITC Rev. 3) and aims to provide a more detailed tool for analyzing international trade. The paper highlights the limitations of the current classification, such as the lack of disaggregated sectoral data and the need for more detailed product lists. It also discusses the methodology for evaluating indirect R&D intensities and the use of the Leontief inverse approach to measure total R&D embodiment. The paper concludes by noting that the new classifications aim to provide a more accurate and detailed tool for analyzing the impact of technology on industrial performance and international trade.This paper by Thomas Hatzichronoglou, published in the OECD Directorate for Science, Technology and Industry's Working Papers series, discusses the methods used to classify OECD countries' industrial sectors and manufactures by level of technology. The paper presents two new classifications: one by industrial sector and one by product. The sectoral classification identifies four groups of industries based on technology intensity, considering both the level of technology-specific R&D expenditure and the technology embodied in intermediate and capital goods. The product classification focuses solely on high-technology products, which are the most technology-intensive. The sectoral classification is based on the International Standard Industrial Classification (ISIC Rev. 2) and covers manufacturing industry. The product classification is based on the Standard International Trade Classification (SITC Rev. 3) and aims to provide a more detailed tool for analyzing international trade. The paper highlights the limitations of the current classification, such as the lack of disaggregated sectoral data and the need for more detailed product lists. It also discusses the methodology for evaluating indirect R&D intensities and the use of the Leontief inverse approach to measure total R&D embodiment. The paper concludes by noting that the new classifications aim to provide a more accurate and detailed tool for analyzing the impact of technology on industrial performance and international trade.