Think tanks (policy research institutes) in the U.S. have played a role in policy making for almost 100 years, though most date from after WWII. At the state level, however, they have been much less prominent, and their activity in regional research has been limited. Three types of state level think tanks can be identified: first, those associated with state government and universities, the latter often specialized; second, small think tanks that exist in large numbers and are primarily committed to advocacy of particular viewpoints; and third, a small group that are independent and similar to national think tanks, such as Rand, which aspire to objective research and analysis with the aim of improving public policy. The Public Policy Institute of California falls into the third category. Its experience offers some useful insights into the effectiveness of such entities, particularly their relevance to regional policy research.