The irreversibility of consumer spending, namely the tendency - in the presence of an income reduction - of individuals and the community not to reduce the consumption standards acquired over time, is a well-known property in the economic literature and accepted by different theoretical paradigms.

One of the strongest explanations derives from the contributions of Thorstein Veblen, who introduced the concept of conspicuous consumption, and the institutional school, in which the irreducibility is traced back to the social determination of consumption spending and in the resulting acquisition of peculiar habits.

The analysis expounds on the research of the genesis of the social role of consumption in the history of economic thought. As it regards, it will be first shown that both in classical economists and in Marx it can be found a social dimension between the determinants of subsistences.

Especially the works of J. Steuart, A. Smith, D. Ricardo show the centrality of historical and social factors in the determination of the subsistences and, more generally, of the minimum level of real wages in the surplus theories. Due to the social structure in which classical political economy developed, we argue that it is not possible to find any explicit reference to the social role of consumption. This role, however, can be singled out, as different textual passages confirm, in the theoretical development made by K. Marx.

Throughout the marxian analysis takes shape the conception of the social role of consumption spending, deriving essentially by the progressive advancement of the capitalist production system and by the change in the relations of production.

In the central part of the work it will be shown the plausible overlapping between the Veblenian analysis of conspicuous consumption and the Marx’s line of reasoning upon the social role of consumption.

The study ends with some notes on the implications that the irreducibility of consumption spending may have on the accumulation process and on economic growth.

Keywords: conspicuous consumption, consumption, income distribution, classical economists, Marx, Veblen, surplus approach.