§ 1. Estimates of the world's population. § 2. Population growth in Europe since 1800. § 3. Increase since 1790 in America. § 4. Relation of population to resources. § 5. Birth rates. § 6. Death rates. § 7. Population growth and intensive cultivation. § 8. Law of increasing and decreasing returns. § 9. Increasing returns in the nineteenth century. § 10. Rhythmic changes of population. § 11. Cumulative dynamic economy. § 12. Individual and general adjustment to static conditions. § 13. Adjustment to dynamic forces. Note on Various meanings of diminishing returns.

§ 1. Estimates of the world's population. The movement of population can be known with approximate accuracy only where a census of the population is regularly taken. This was done nowhere until the end of the eighteenth century, and even now is done for only a small part of the world. In all other places and times, movements of population can only be estimated, usually from very insufficient data. It is certain, however, that in ancient times a considerable density of population was attained only in a few centers of empire (Egypt, Babylon, Persia, Greece, Rome, etc.), where peace, trade, fertile soil, comparatively advanced methods of agriculture, accumulated wealth, and extended political power with tributes from subject people were combined in an exceptional degree. Nearly the whole of the habitable globe was possessed by hunting tribes or by pastoral nations very sparsely peopling the lands. It has been estimated that the population of the earth at the death of Augustus (19 a.d.) was about 50 million.1 Since 1800 there is more of knowledge

1The Italian economist Bodio's estimate is 54 million.

Repeating the warning that these figures are mere estimates, it may yet be believed that a great increase had taken place between the first century and the year 1800, of which a large part, about half, had been in the Chinese Empire, numbering then about 300,000,000 people. But the most enormous increase occurred between 1800 and 1910, about one billion people being added to the world's population, the total in 1910 being nearly three times as great as it was in 1800.

The population of Europe is said hardly to have exceeded 50,000,000 before the fifteenth century3 at which time England had about 2,500,000 people.4 Population grew rapidly from the end of the fifteenth century with the increase of centralized government, better agricultural methods, foreign trade, inventions, etc. An enormous loss of life took place on the Continent during the Thirty Years' War (1618-1648), still a term of dread in Germany which, during that time, lost and less of guess work in the figures, which have been estimated as follows:2 through violence, pestilence, and famine about two thirds of its former population. Despite numerous wars the population of Europe, according to a widely quoted estimate, was 130,000,000 in 1761,5 and was about 175,000,000 in 1800.6

2 The first column was compiled from various authorities by Prof. W. F. Willcox, in his paper "The Expansion of Europe"; from which we have derived the yearly arithmetic increase and percentage of increase by decades.

3Mulhall's "Dictionary of Statistics."

* At accession of Henry VII, 1485 a.d. See Traill's "Social England," vol. III, p. 129.



of the



Yearly arithmetic increase in preceding decade; millions


increase in




................ 640


• •



• •

• •


................ 780




................ 847




................ 950




................ 1,075




................ 1,205




................ 1,310




................ 1,439




................ 1,488




................ 1,543




................ 1,616



§ 2. Population growth in Europe since 1800. Population increased in Europe at an unprecedented rate in the nineteenth century. It numbered about 175,000,000 in 1800, over 250,000,000 in 1850, about 390,000,000 in 1900, and 400,-000,000 in 1910. Many things helped to increase the food-supplies available for Europe. The resources of the American continent were hardly touched until the great western movement of population began and new agencies of transportation brought American fields thousands of miles nearer to European markets. The improvement of machinery and of other economic equipment in Europe, and better methods of cultivation aided to increase production rapidly. Population followed, tho not with equal step. The increase has gone on at undiminished pace in eastern and southeastern countries but recently there has been a notable decline in the rate of increase in several of the countries of western Europe. France has been nearly at the stationary stage since the beginning of the twentieth century, and England probably will have reached it by the middle of the century. The great war begun in 1914 must, in the warring nations, greatly reduce the marriage rate, increase the death rate, and reduce the birth rate, until the end of hostilities. The men killed in battle are fewer than the children never to be born, who but for the war would have come into the world.

A stationary or declining population throughout Europe sometime after the return of peace is a possibility. But this does not destroy the significance of the fact that there is inherent in humanity a great potential power of increase, the realization of which would be disastrous, the limiting of which either by crude objective means (famine, war, illicit measures) or by volitional means is inevitable. It does not disprove the great biologic proposition in the Malthusian doctrine.

5 Estimate of Sussmilch, the famous statistician of the eighteenth century. 6 Estimate of Levasseur, cited by Willcox.

Population in U.S. 1790-1910, White and Negro