Differential and absolute ground rent

Differential ground rent and absolute ground rent are concepts used by Karl Marx in the third volume of Das Kapital to explain how the capitalist mode of production would operate in agricultural production, under the condition where most agricultural land was owned by a social class of land-owners who obtained rent income from those who farmed the land. The farm work could be done by the landowner himself, the tenant of the landowner, or by hired farm workers. Rent as an economic category is regarded by Marx as one form of surplus value just like net interest income, net production taxes and industrial profits.'Marx postponed his discussion of rent until the third volume of Capital, but the sheer quantity of his writing on the topic (more than 600 pages in total) indicated that he did not take the matter lightly. (...) Marx's own work was lengthy, inelegant and, above all, tentative; not one of the several hundred pages written in Capital and Theories of Surplus Value on the topic was ever approved for publication by the author.' Differential ground rent and absolute ground rent are concepts used by Karl Marx in the third volume of Das Kapital to explain how the capitalist mode of production would operate in agricultural production, under the condition where most agricultural land was owned by a social class of land-owners who obtained rent income from those who farmed the land. The farm work could be done by the landowner himself, the tenant of the landowner, or by hired farm workers. Rent as an economic category is regarded by Marx as one form of surplus value just like net interest income, net production taxes and industrial profits. In good part, Marx's theory is a critique of David Ricardo's Law of rent, and it examines with detailed numerical examples how the relative profitability of capital investments in agriculture is affected by the productivity, fertility, and location of farmland, as well as by capital expenditure on land improvements. Ricardo conceptualized rent income essentially as an 'unearnt' income in excess of true production costs, and he analyzed how some farm owners could obtain such an extra profit because of farming conditions which were more favourable than elsewhere. Marx aims to show that capitalism turns agriculture into a business like any other, operated for purely commercial motives; and that the ground rents appropriated by landowners are a burden for the industrial bourgeoisie both because they imply an additional production-cost and because they raise the prices of agricultural output. More specifically, Marx intended to show how the law of value governed capitalist farming, just like it governed capitalist industry. The peculiarity of capitalism in agriculture is that commerce has to adapt to physical factors such as climate, altitude and soil quality, the relative inelasticity of agricultural supply, and the impact of bad harvests on international prices for farm products. Eventually, however, the production of farm products is completely reorganized according to the exchange-value of farm output – foodstuffs are then produced mainly according to their expected trading value in the market (this is not always completely true, e.g. because it may be feasible to cultivate only a limited variety of crops, or run a limited variety of cattle on particular lands, or because there is no perfect knowledge about what the market will do in the future, if there is great price volatility, climate uncertainty etc.). According to Marx, the operation of the law of value and the formation of prices of production was modified in capitalist agriculture, because prices for farm output were co-determined by land yields and land ownership-rents quite independently of labor-productivity. For example, a poor harvest in a major agricultural region due to adverse weather conditions, or the monopolization of the supply of farmland, could have a big effect on world market prices for farm products. Marx extends his theory of agricultural rents to building rents and mine rents, and considers the effect of rent income on land prices. This theory is the least known part of Marx's economic writings, and among the more difficult ones, because earnings from farm work can be affected by many different variables, even at a highly abstract level of analysis. However the theory became very important to neo-Marxists such as Ernest Mandel and Cyrus Bina who interpreted late capitalism as a form of increasingly parasitic rentier capitalism in which surplus profits are obtained by capitalists from monopolising the access to resources, assets and technologies under conditions of imperfect competition. Marxist writers such as Cyrus Bina have extended the concept of rents to oil rents. Marx's main texts on rent theory can be found in the second (edited) volume of Theories of Surplus Value and in Part 6 of Capital, Volume III. Gibson & Esfahani (1983) comment that: Another possible reason for the relative obscurity of the theory is that in modern macro-economic statistics and national accounts, no separate and comprehensive data are provided on the amounts of land rents and subsoil rents charged and earned, because they are not officially regarded as part of value-added, and consequently are not included in the calculation of GDP (except for the value of productive lease contracts). The tax data on land transactions are unreliable because of valuation inconsistencies. The underlying conceptual argument in national accounts is, simply put, that such rents do not reflect earnings generated by production and are unrelated to production, and consequently that such earnings do not make a net addition to the value of new output. Implicitly, therefore, many land rents are treated as if they are a transfer of income. Typically only the annual value of expenditure on land improvements and the value of leases of productive equipment are recorded as 'productive', value-adding earnings.