There are various Marxian approaches towards understanding monopoly. The most direct and sustained is the monopoly capitalism perspective (for example, Baran & Sweezy, 1968; Magdoff & Sweezy, 1987; Foster, 2014a), tied to the Monthly Review magazine. This uniquely American school of thought takes monopoly as the latest developmental stage in the capitalist mode of production. Its main authors argue that the 19th-century capitalism was shaped by similarsized producers in an environment of intense industrial competition. The main argument is that, since the 1970s, capital increasingly escapes production and enters a speculative domain of financialization. This results in monopoly-finance capitalism, a specific regime of capital accumulation benefitting a tiny minority of capital lenders and shareholders, transnational companies, and corporate owners and managers (Magdoff & Sweezy, 1987; Sweezy, 1994; Foster, 2016). According to these authors, capitalism has now entered a stage of increasing concentration of capital in the hands of fewer and fewer companies and owners.

While this thesis holds some weight towards describing the contemporary snapshot of GAFAM's oligopoly, it cannot explain the specificities of the platform business model, commodity chains on digital platforms we described in Chapter 2, or legal forms necessary for the reproduction of capital through platforms. Moreover, it does not engage in theorizing value, surplus value, and money but, instead, replaces it with the concept of the economic surplus (Baran, 1956/ 1973; Barclay et al, 1975), thus severing ties with some of Marx's central concepts. Hence, monopoly as a stage in capitalist development does not explain how the platform economy went through its successive stages of competition, financial collapse, current oligopoly, and regulatory challenges, nor does it take sufficient account of the legal forms necessary to establish monopoly over technical discoveries through copyright and patents. From our perspective, there are three approaches grounded in Marxian theories that are useful for the analysis of digital platforms. First, understanding that monopoly is not a stage in capitalist development but a dynamic process enabled and/ or constrained by a specific regulatory regime. Second, understanding that monopoly is a process of concentration and centralization of capital visible in mergers and acquisitions across the history of capitalism.