From the Zig-zag to the Précis and to the Formule : Why Did François Quesnay Change Twice the Form of His Tableau ?

From 1758 to 1768 the Tableau Économique of François Quesnay took successively three forms, the Zig-zag, the Précis, and finally the Formule. This article explains the reasons for the two form changes, from the Zig-zag to the Précis and from the Précis to the Formule. From Philosophie rurale (1763), Quesnay improves the tool that the Tableau already was so that it can account for France's gradual transition from a current net production rate of 30 percent to a future rate of 100 percent. The Zig-zag could not account for the progress of agriculture. The Précis, which is a compacted Zig-zag, remains too rigid. It is a transitional form toward the modified Précis and then toward the Formule. The Formule is a very efficient and flexible tool. The Formule affirms a stock-flow approach. It facilitates the start of the exchanges between the three classes of society. It gives an account simultaneously of the monetary payments and of the real deliveries between the different classes. From an economic point of view, the Formule appears superior to the Zig-zag and the Précis. It constitutes for that reason the definitive form of the Tableau.