The purpose of this paper is twofold: to provide a brief survey of recent approaches to the measurement of total factor productivity; and to comment on some of the special problems which are associated with capital. Thus in Sections I-IV below, four approaches to the measurement of total factor productivity are outlined, while Section V compares and contrasts the approaches. In Section VI, I consider how the various approaches have to be modified when welldefined rental markets for components of the capital stock do not exist (the usual case).