ABSTRACT
When the demand for agricultural goods increases, the extension of cultivation on lands of the same grade sets no significant economic problem: the same marginal methods are used and no changes in prices, wages or rents occur. A limit is reached when the corresponding land becomes scarce. Then the prices of the agricultural products rise and cultivation is extended to a new land or, alternatively, more intensive methods are substituted for the present ones on the same land. To isolate extensive cultivation proper, we assume a unique method of cultivation on each type of land (because of that one-to-one correspondence, it is indifferent to refer to a land or an agricultural method). Sraffa (1960) argued that the order of cultivation is not a natural phenomenon and may change with the exogenous distribution variable. Let the rate of profit be given. Post-Sraffian studies have shown that the extension of cultivation follows a simple rule: the lands are cultivated in the order of the decreasing real wages they yield for a zero rent. Since that order is well defined, there exists a unique equilibrium for each demand basket, flukes apart. The equilibrium is characterized on the physical side by a unique set of cultivated lands and, on the value side, by a unique associated set of prices, wages and rents.
