The aim of the research project is to identify the effectiveness of R&D tax incentives using the evidence gathered by econometric evaluation studies of R&D tax incentives in the past 20 years. The main contribution of the project is to “unpack” the positive effect of tax incentives on R&D found in most evaluation studies by considering the type of tax scheme (e.g. volume vs incremental) and its characteristics (e.g. tax rate, ceiling, differentiation by size class, carry forward and carry-backward rules). So far, meta-studies on the effectiveness of R&D tax credits rarely looked at design features, and if they did so, only a few features (e.g. volume vs incremental schemes) were considered. The research applies the method of meta-analysis.