In this classic book, originally published in 1968 by University of Toronto Press, John Dales proposed a new policy instrument for tackling pollution problems, namely 'markets in pollution rights'. Dales was one of the first economists to put forward such a solution, and in subsequent years a system of emissions trading has evolved which is now a centrepiece in international discussions of how to address the problem of global climate change. Policymakers around the world are still exploring ways in which the marketable-rights approach may be used to increase the effectiveness of environmental regulation. From this perspective, readers will find this short and extremely readable book of great interest - as a return to the basic idea in its original form and a lucid justification for its continued use.