Think tanks have a long established role in generating ideas. The UK Fabian Society is one of the oldest. Famous US examples include Brookings and the American Enterprise Institute. The most visible tend to focus on policy innovation. In the past, they acted as intermediaries between research done in universities and practitioners in government and elsewhere. The best think tanks can act as catalysts, combining research, policy ideas, and prompts for practical innovation in advance of policy change. A good recent example is Demos’ work on the future evolution of personal budgets for recipients of care from government.