Kevin and I went to a talk this week and found out about a very under-utilized resource on campus, the Research Data Center (RDC). It is one of only 9 RDCs in the U.S., and it is the only location where you can access non-public demographic, health, and economic data that contain detailed information on geographic location and/or other characteristics about firms or households. For an overview of all the confidential data you can seek access to, look over the CRDC's data page, and specific details about each can be found at the Center for Economic Studies Data Page. The application process is described as "rigorous and lengthy", but the people at the center seem very friendly and eager to help more researchers use their data. For a list of other data resources on campus, check out the UC Data resources page.