the AR's operation. Typically, it is said that it comprises a money form, a competition form, a wage form, a state form, and an international regime, but it can encompass many more elements than these. Generally speaking, MRs support ARs by providing a conducive and supportive environment, in which the ARs are given guidelines that they should follow. In cases of tension between the two, a crisis may occur. Thus this approach parallels Marx's characterisation of historical change as driven by contradictions between the forces and the relations of production (see historical materialism). Translation and definition Bob Jessop summarises the difficulties of the term in Governing Capitalist Economies as follows: "The RA seeks to integrate analysis of political economy with analysis of civil society and or State to show how they interact to normalize the capital relation and govern the conflictual and crisis-mediated course of capital accumulation. In this sense, régulation might have been better and less mechanically translated as regularization or normalization" (p 4). Therefore, the term régulation does not necessarily translate well as "regulation". Regulation in the sense of government action does have a part in regulation theory. History of modes of regulation Robert Boyer distinguished two main modes of regulation throughout the 19th and 20th centuries: The "mode of regulation of competition" (1850–1930). It consisted of a first mode of regulation, from 1850 to the beginning of the 20th century, that Boyer called "extensive mode of regulation", characterized by low productivity gains, important part of the output dedicated to equipments, and high competition. The second period is called "intensive mode of regulation without mass consumption", because it consists of high productivity gains (thanks to Taylorist methods) and the production of consumption commodities. The "monopolist mode of regulation" (after 1930), characterized by high productivity and mass consumption. The Fordist system made possible a regular growth of economic output and an increase in income at the same time. Crisis Regulationist economists distinguish between cyclical and structural crises. They study only structural crises, which are the crises of a mode of regulation. From this distinction, they have formulated a typology of crises that accounts for various disarrangements in institutional configurations. According to its initial objective, which was to understand the rupture of the Fordist mode of regulation: Exogenic crises are due to an external event; they can be very perturbing but cannot endanger the mode of regulation, and even less