Lucas on involuntary unemployment

The aim of this paper is to examine critically Lucas' arguments against Keynes's General Theory and in particular against Keynes's concept of involuntary unemployment. It comprises two main parts. In the first part of the paper, the author questions Lucas's claim that Keynes betrayed the equilibrium discipline by freeing himself from the postulates of optimising behaviour and market clearing. In the second part, Lucas’ three arguments against the involuntary unemployment concept are discussed—first, that there is no rationale for drawing a distinction between two sorts of unemployment; second, that every economic outcome features the voluntary and the involuntary jointly; and third, that alternatives to unemployment are always present.