Michael Sandel, Harvard Professor of Government, delivers four lectures about the prospects of a new politics of the common good. The series is presented and chaired by Sue Lawley. Sandel considers the expansion of markets and how we determine their moral limits. Should immigrants, for example, pay for citizenship? Should we pay schoolchildren for good test results, or even to read a book? He calls for a more robust public debate about such questions, as part of a 'new citizenship'.