Gregory King - Works

Works

"The first great economic statistician," as Richard Stone calls him, came a generation after John Graunt and William Petty and continued their work. Their work was mainly published, but King's was not: he was a confidential advisor to the government. Material from his manuscripts appeared in the writings of his friend Charles Davenant and—a century later—in Adam Smith's Wealth of Nations (Book I, Chapter VIII), and in An Estimate of the Comparative Strength of Britain by George Chalmers.

King's manuscript Natural and Political Observations and Conclusions upon the State and Condition of England, 1696, contains estimates of the population and wealth of England at the close of the 17th century. It describes the demographic characteristics of the population of England and Wales: age, gender, marital status, numbers of children, servants and "sojourners." King also calculates the amount of beer, ale, and malt consumed annually in England. These estimates are based on intelligent inferences from data available to the state as a by-product of its taxing activities. However, in more speculative mood, King considers the present and future level of world population. His Notebook contains projections of world population: around AD 5000 or 5500 the world would be "fully peopled" with 10 times the population of 1695.

Of the Naval Trade of England, 1688, and the National Profit then Arising thereby," written in 1697, is King's statistical summary of the trade and wealth of England, 1600-1688. He calculated the increases in shipping (for war and trade), customs, coinage, buildings, fortresses, and the purchases and improvements of land.

Gregory King's Law, or the "King-Davenant law," is an estimate of by how much a deficiency in the supply of corn will raise the price of corn. It appears in Davenant's Essay upon the Probable Methods of making a People Gainers in the Balance of Trade. Since the early 19th century it has usually been attributed to King.

The relevant passage is this:

It is observed that but one-tenth the defect in the harvest may raise the price three-tenths, and when we have but half our crop of wheat, which now and then happens, the remainder is spun out by thrift and good management, and eked out by the use of other grain; but this will not do for above one year, and would be a small help in the succession of two or three unseasonable very destructive, in which many of the poorest sort perish, either for want of sufficient food or by unwholesome diet.

We take it that a defect in the harvest may raise the price of corn in the following proportions:

Defect raises the price above the common rate 1 tenth ............... 3 tenths 2 tenths ............... 8 tenths 3 tenths ............... 16 tenths 4 tenths ............... 28 tenths 5 tenths ............... 45 tenths

So that when corn rises to treble the common rate, it may be presumed that we want above one-third of the common produce; and if we should want five-tenths or half the common produce, the price would rise to near five times the common rate." (The Works of Sr William D'Avenant Kt, vol. ii, pp. 224, 225, edited by Sir C. Whitworth, London (1771)).

In the 19th century Whewell and Jevons re-expressed the estimate as an equation. The estimate raises several questions. To whom should it be attributed, Davenant or King? How was it constructed? How accurate is it? Stone reviews the considerable literature on these questions.