The Economics of Time and Ignorance is one of the key works in the development of modern Austrian economics. Building on the work of Hayek, Lachmann and Shackle,its authors developed a powerful critique of neo-classical economics, in particular of its over deterministic models and its pretence of knowledge. The work is reprinted here in full and is supplemented by a substantial new introduction which outlines the major developments in the area since the book’s original publication a decade ago.