In this study, we examine choices in voluntary superannuation contributions by Australian income earners. In particular, we focus on salary sacrifice contributions, which could attract a tax benefit of up to 30 percentage points. This study aims to evaluate how effective tax incentives are in stimulating salary sacrifice participation. Using a regression discontinuity framework, we measure the response of individuals to different levels of tax concessions on salary sacrifice contributions. Results indicate that current tax incentives have a limited effect, if any, on the decision to make salary sacrifice arrangements. This result is consistent with more recent empirical research from the Northern Hemisphere. It is likely that the lack of response is due to the complexity of the incentive schemes in Australia and competing vehicles for long-term savings.