The development of think tanks in the US coincides with a state apparatus that has grown in size and taken on ever more complex tasks. Foundations such as the Rockefeller Foundation, the Ford Foundation, the Brookings Institution and the Carnegie Endowment contributed with research and reports to meet the social and economic challenges of industrialism. During the Second World War, organisations such as the Rand Corporation came along to analyse defence and security policy.

Everything was objective, dispassionate and based on research. The think tanks worked close to federal power and its institutions. Almost without exception, political solutions were proposed for social problems. But during the social eruptions of the late 1960s, this approach was called into question. The liberal, progressive era was succeeded by a conservative era. A new type of think tank developed: ideological and often conservative or neoliberal. The emphasis was less on research and more on ideas, pr...