This chapter discusses the measurement of expenditure on the performance of research and experimental development (R&D), the sources of funds for the performance of R&D and expenditures for R&D performed in other statistical units. The measurement of gross domestic expenditure on R&D (GERD), which covers all expenditures for R&D performed in the economy during a specific reference period is the principal R&D indicator at country level. GERD, and the GERD/GDP ratio, are used for international comparisons. The chapter discusses the measurement of expenditures and flows in each of the four sectors of the manual where R&D is performed, Business enterprise, Government, Higher education and Private non-profit, and the flow of funds from the Rest of the world sector for the performance of R&D in the other four sectors. With the decision to treat the expenditure on the performance of R&D as a capital investment in the System of National Accounts (SNA), and the need for better statistics on the globalisation of R&D, more information is needed and guidance is provided on what to collect. There is also discussion of the use of the statistics, of which the GERD/GDP ratio is an example, as is the estimation of the capital investment in R&D in the SNA. There is also the need to be able to analyse data at the level of the individual statistical unit in order to have a better understanding of the dynamics of R&D performance and funding.