This volume brings together and updates the classic work of the late Scottish political economist Duncan Black. It contains a revision of both "The Theory of Committees" and "Elections", and "Committee Decisions with Complementary Valuation" (with R.A. Newing) based on the notes and annotations of Duncan Black before his death in 1991. The work is then extended by the addition of five related manuscripts and a complete bibliography of this work. By publishing this work in one single volume, one can witness the contributions made by Duncan Black to public choice and social choice. This includes the median voter theory, "cyclical majorities", voting rules and strategic behaviour, multidimensional spatial theory, and determining preferences from ballots. This volume should be required reading for all scholars and students of formal political science, public choice or social choice theory.