Evaluating the possible consequences of R&D tax incentives before their introduction is challenging, not least because the details of the system remain unknown, and because the ultimate reactions and responses of various actors involved remain uncertain. In order to shed some light on the issue, this reports studies the results of surveys targeting the representatives of Finnish firms by employing statistical and econometric tools. R&D tax incentives have become increasingly common among the industrialized countries, and the trend seems to continue. Even though R&D tax incentives and direct support are in essence substitutes, they seem to co-exist, and in a sample of OECD countries there is a (very weak) positive correlation between their relative magnitudes. The rather broad (but uneven) empirical literature on the topic provides some evidence on the complementarity between business enterprise R&D and its tax incentives : A mean estimate which has, however, a considerable variance across internationally available scholarly studies suggests that a dollar in R&D tax incen-tives stimulates one to two per cent additional R&D above the tax dollar spent. Both Finnish and international survey findings suggest that firms have a (slight) preference for R&D tax incentives over direct support, and that they would increase their innovative efforts in response to additional incentives. Growth-orientated, innovative, and/or externally collaborating firms seem to be more responsive to additional support, although there is no statistically significant difference in responsiveness by the support type.