In the short video below, Bruce Greenwald and Joseph Stiglitz introduce their work on the learning society and the idea of development. They argue that the most important feature of economic and social development is the creation and diffusion of knowledge, rather than capital accumulation per se, which has been the traditional focus of much economic theory.
They also argue that learning takes place mainly in institutions rather than in markets, and that markets are in general inefficient due to the presence of imperfect information. State intervention is necessary to correct such market failures.
The Political Economy of Development 