According to World Bank, ″Gross domestic expenditures on research and development (R&D) include both capital and current expenditures in the four main sectors: Business enterprise, Government, Higher education and Private non-profit. R&D covers basic research, applied research, and experimental development.″[3]
According to United Nations Economic Commission for Europe, ″Research and development (R&D) expenditure as a proportion of Gross Domestic Product (GDP) is defined as the total intramural expenditure on research and experimental development (R&D) performed in the national territory during a specific reference period expressed as a percentage of national gross domestic product (GDP).″[4]
According to the Organisation for Economic Co-operation and Development, ″Gross domestic spending on R&D is defined as the total expenditure (current and capital) on R&D carried out by all resident companies, research institutes, university and government laboratories, etc., in a country. It includes R&D funded from abroad, but excludes domestic funds for R&D performed outside the domestic economy.″[2]