This report presents new evidence on the impact of R&D tax incentives and direct funding of business R&D, drawing on distributed cross-country and firm-level analyses undertaken as part of the first phase of the OECD microBeRD project (2016-19). This “distributed” approach facilitates a harmonised analysis of confidential business R&D and tax relief microdata in 20 OECD countries. microBeRD provides new insights into the effectiveness of R&D tax incentives in encouraging business R&D in the OECD area and the heterogeneity of effects both within and across OECD countries, including the underlying impact mechanisms. The report contributes to the debate on the role of R&D tax incentives in the policy mix by providing additional comparative evidence on the effects of alternative business R&D inducement incentives.