Signature requirements and citizen initiatives: Quasi-experimental evidence from Germany

Signature requirements are often used as hurdles to prevent overuse of direct democratic instruments such as citizen initiatives. We evaluate the causal effect of lowering signature requirements on the number of observed citizen initiative petitions. Based on municipal-level data for Germany, we make use of changes in signature requirements that occur at specific population thresholds to build an identification strategy using a regression discontinuity design. We find that reducing the signature requirement by 1 % point increases the probability of observing an initiative petition in a given city-year by 8-10 % points.