Public Protests, Social Media and Policy Making Public Protests, Social Media and Policy Making *

We explore the limits of petitions and public protests as mechanisms to aggregate dispersed information. We show that if citizens’ signals are not sufficiently precise, information aggregation is impossible, even if the conflict with the policy-maker is small, no matter how large is the population of informed citizens. We characterize the conditions on conflict and the signal structure that guarantee information aggregation. When these conditions are satisfied, we show that full information aggregation is possible as population grows to infinity. When they are not satisfied, we show that information aggregation may still be possible if social media are available. Marco Battaglini Department of Economics Cornell University Ithaca, NY 14853 ∗For useful comments and discussions we thank Stephen Coate, Andrew Little, Thomas Palfrey, Wolfgang Pesendorfer and seminar participants at Cornell, Princeton, UCLA and UCSD. We thank Nemania Antic, Yanlei Ma and Ross Milton for outstanding research assistance.