Introduction

I have often asked myself why Appendix D of Piero Sraffa's (1960) book does not mention Sir William Petty, though his works are abundantly present in Sraffa's library (see De Vivo, 2014). Maybe some of the friends working on Sraffa's papers will satisfy my curiosity.

The question has not to do with the “corn model” but with the existence of an “economy which produces more than the minimum necessary for replacement” (Sraffa, 1960, 6).

To my knowledge Petty was the first author to clearly spell out the importance of the existence of a surplus of necessaries (see below section 3). Whether it is made of corn, agricultural products, subsistence goods or basic commodities, the concept of a physical surplus is at the core of Sraffa's investigation. In Sraffa's Production of Commodities (parts 1 and 2), the physical quantities of both the inputs and the outputs are given and are not related to prices; this is a fundamental assumption. From chapter 2 onward there is also a physical surplus, and “the right-hand side of the resulting sum-equation (or gross national product), will contain, besides all the quantities which are found on the lefthand side (or means of production and subsistence), some additional ones that are not” (ibid., 6).

This chapter offers a quick overview of the story of the role agricultural surplus and of the theory of wealth from mercantilism to Smith. Section 2 examines mercantilism, while section 3 deals with Petty and Cantillon. Section 4 examines the contribution of Francois Quesnay, and section 5 presents some elements of Adam Smith's view of wealth.

Moreover this chapter provides an opportunity to examine the scope and method of the early political economists up to Smith. The classical political economists tackled the issue of the wealth of nations, and some notions they elaborated are still of crucial importance in today's debates on development economics.