Participation Cost Estimation: Private Versus Non-Private Study
  In our study, we seek to learn the real-time crowd levels at popular points of interests based on users continually sharing their location data. We evaluate the benefits of users sharing their location data privately and non-privately, and show that suitable privacy-preserving mechanisms provide incentives for user participation in a private study as compared to a non-private study. 
Joshua Joy, Sayali Rajwade, Mario Gerla
cs.CR