Numerical fiscal rules are implemented to counterbalance the deficit bias in budgetary policy. However, the effectiveness of these rules in limiting public debt has been a matter of discussion. Over the recent years, an increasing number of studies therefore tried to test the actual effectiveness of fiscal rules. In this project, we intend to conduct a meta-analysis which condenses the existing evidence. We particularly focus on the criticism that rules may be the endogenous reflection of fiscal preferences and control for a comprehensive set of variables that try to capture fiscal preferences. Further, we particularly take into account design features such as the estimation method or the application of dedicated identification strategies that may systematically influence levels of statistical significance in primary studies.