Subsidies for research and development (R&D) are an important innovation policy tool. The economic rationale behind R&D subsidies is that private sector R&D is lower than socially desirable due to positive externalities and financing constraints. R&D subsidies are often designed as direct, project-based grants. Companies apply for them at public funding bodies who administered applications and make funding decisions on a case-by-case basis. An alternative way of granting R&D subsidies is through tax credits. Research shows that both forms of R&D subsidies can trigger additional R&D, but the evidence also suggests that the extent to which R&D subsidies initiate and expand R&D in recipient firms depends on the characteristics of the firm and the type of project that is subsidized.