Before we proceed to more specifically identify the criteria of periodization, a few methodological comments are here in order. First we should stress that periodization cannot be properly conceived at the highest level of abstraction referring to the Cmp and surplus extraction. on the other hand, contrary to those approaches (of either a structuralist or a post-keynesian inspiration) focusing on historically specific social formations, periodization should rather be conceived at a level of abstraction regarding the world economy in its totality, the specific organizational structure and the (vertical and horizontal) pattern of accumulation, and the particular forms of surplus value extraction. according to marx (1973: 408), ‘[t]he tendency to create the world market is directly given in the concept of capital itself. every limit appears as a barrier to be overcome.’ it is also pointed out that the world market constitutes ‘the very basis and living atmosphere of the capitalist mode of production’ (marx, as cited in kincaid 2005: 115). and though marx has not extensively elaborated on the world economy, as pointed out (kincaid 2005: 115), ‘[i]t is clear … that he rejected any idea of individual national economies as passing through a fixed series of stages’. other marxist theorists, notably Trotsky, have also stressed the methodological precedence of the world economy. Based on his thesis of combined and uneven development, Trotsky points out that

it is obvious that this latter statement becomes even truer in the current epoch of a rapid globalization and an increasingly transnational accumulation of capital.