I would probably start with Ch6 in his _Les mots et les choses_ (1966), on mercantilism, and then bring in some secondary texts by economists, e.g. Jack Amariglio 'The Body, economic discourse, and power: an economist's introduction to Foucault' (HOPE 1988), Iara Vigo de Lima Onate 'Paradigms and epistemes in the history of economic thought' (SCEME Working Paper No. 8, 2004) Deleuze's _Foucault_ (1986) is still one of the most perceptive general appreciations of his work. Matthias Klaes