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).

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).¹

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.

In particular, agricultural surplus is a puzzling issue for development theories and policies. As for theoretical issues: set yourself in a low-income country in sub-Saharan Africa, and some decisive questions do arise. Is agricultural productivity above bare subsistence a necessary condition for economic growth? Successful economic growth requires a process of structural change in the composition of the gross domestic product, which should include fewer primary commodities and be comprised of more and more medium and high-technology manufactures (see Chang, 2002). But then why bother about improvements in food production? All the more so, when we see that the share of employment in agriculture is declining and, in developing countries, most of the people are working in the service sector too. Where should W Arthur Lewis’s “disguised unem­ployed” people move to when leaving the primary sector (see Lewis, 1954)?

2.