Can social movements cause political change? If they cause political change, at what point are their effects long-term lasting? This study addresses these questions by doing a quantitative estimation of the short and long term political effects of the highly digitalized “15M” Spanish social movement that starts in 2011. I exploit the fact that the beginning of the movement was random to use a Regression in Discontinuity Design to estimate short-term effects. I exploit the geographical variation of weather to isolate the causal effect of the movement using 2SLS Instrumental Variables to estimate the long-term effects. Results show significant effects of 15M movement on short-term political opinion and long-term but diminishing effects of 15M movement on vote intention and behaviour. I also found heterogeneous short-term effects: students and individuals with left political preferences present a higher effect of the 15M movement. Low-educated population presents a significantly lower effect.
