Disclosed are techniques for privacy preserving mobile demographic measurement of individuals, groups, and locations over time and space. A method of estimating demographic information associated with a user of a mobile device and/or a location while preserving the privacy of the user based at least in part on a location estimate of the mobile device of the user includes receiving an estimated geographical location of the mobile device of the user and receiving a time at which the mobile device was at the estimated geographical location. The method includes assigning substitute identifiers for the geographical location and the time at which the mobile device was at the estimated geographical location. The method includes associating the geographical areas substitute identifiers with demographic information and estimating demographic information associated with the user of the mobile device based on the substitute identifiers and based on the demographic information associated with substitute identifiers.