This study analyzes changes over time in long-lasting state performance funding systems for higher education. It addresses two research questions: First, in what ways have long-lasting systems changed over time in funding levels, indicators used to allocate funds, and measures used for those indicators? Second, what political actors, actions, and sociopolitical conditions explain those changes? The authors' analysis draws on two theoretical perspectives: policy implementation theory and program sustainability theory. Policy implementation theory focuses on how policies change after they have been enacted, focusing on the interaction between higher-level officials who design and authorize policies and lower-level or "street level" officials who ultimately implement the policies. The authors particularly draw on the "bottom up" perspective, which focuses on how the interests, beliefs, knowledge schema, and experiences of lower-level implementers shape their views of a policy and thus their willingness to support it and in what form. Program sustainability theory addresses the factors that promote program continuation and the maintenance of effectiveness. Key clusters of factors that have been identified as influencing program continuation are ones pertaining to the design of the program, the organizational setting in which it housed, and the wider community environment in which it is operating. To answer these questions they investigated the experiences of two states with long-lasting performance funding systems: Tennessee, which pioneered performance funding in 1979; and Florida, which launched it in 1994. For both states, they analyzed publications issued by state agencies and independent researchers, and conducted interviews with top executive branch officials and staff, state legislators and staff, officials of state higher education boards, presidents and other top officials of several colleges, and state business leaders. [This Brief is based on CCRC Working Paper No. 18, "Continuity and Change in Long-Lasting State Performance Funding Systems for Higher Education: The Cases of Tennessee and Florida".]