Contributor(s): Professor Oliver Hart | This lecture launches two new annual lecture series, the Coase Lecture and the Phillips Lecture. These names reflect the authorship of the two most famous articles ever published in Economica (the 'Phillips Curve' article was the most heavily-cited macroeconomics title of the 20th century; Ronald Coase won the Nobel Prize for his work on the theory of the firm which began with his Economica article). In this inaugural Coase lecture, Oliver Hart will discuss how his recent work with John Moo