In order to comprehend the ontological construction below, please refer to the respective posts for all notions in italic.
An income increase that comes with the market exchange of goods is profit. The income is given in the form of commodities, traded on the market. With the rise of income, the goods can be exchanged profitably, and the process repeats its course in self-propagating manner as economic profit, normal profit, or accounting profit. So not only a particular increase in income is a profit on the side of supply – and consumer surplus on the side of demand, – but all the income is generated through the profitable exchange of products as otherwise the exchange in itself is deprived of sustainable ground. To achieve a profit is to meet the ultimate criterion for economic efficiency.
Historical Backdrop
• WILLIAM PETTY The Economic Writings of Sir William Petty: surplus.
• ANNE-ROBERT-JACQUES TURGOT Reflections on the Formation and Distribution of Wealth: profit as revenue.
• JULES DUPUIT On the Measurement of the Utility of Public Works: relative utility.
• ALFRED MARSHALL Principles of Economics: consumer surplus and producer surplus.
• PIERO SRAFFA Production of Commodities by Means of Commodities: surplus.