§ 5. Birth rates. The increasing population has not been due to any general increase in the birth rate. In most countries where there are any records it has been decreasing, and in some cases more rapidly than has the death rate. The world's birth rate in 1911 is estimated to be 36.5 per thousand of population; that of the more advanced industrial countries is much less. In the quarter century between 1886 and 1912 the birth rate decreased in certain countries as follows:

 

Birth rate

 
 

1886

1912

Decrease

Australian Commonwealth ...................

35.4

27.2

8.2

Austria ...............................

38.3

31.4

6.9

United Kingdom .................

32.8

24.0

8.8

France ....................

23.9

19.0

4.9

German Empire ...................

37.0

28.3

8.7

Hungry ......................

45.6

36.3

9.3

Netherlands .....................

34.6

28.1

6.5

Denmark ......................

32.6

26.7

5.9

Norway ...........................

31.1

25.4

5.7

Sweden .......................

29.8

23.7

6.1

Italy ....................

37.0

32.6

4.4

Spain ........................

36.7

31.9

4.8

§ 6. Death rates. A general decrease of the death rate makes possible a growth of population even with a decreasing birth rate. The food production has been increasing and famines have been decreasing, while great improvements in medical and in sanitary science have at the same time been made. The death rate in a community is a rough index of its general welfare: the death of a large proportion of the children before they arrive at maturity indicates poverty or ignorance. The urban death rate in Europe in the Middle Ages was tremendously high, but during the nineteenth century, as a result of engineering and sanitary progress, it sank nearly to that of the country districts. The race of man, ever since the beginnings of volitional control, has had a smaller death rate relative to the total number of individuals coming into existence than has any other species of living creatures. Even in the most miserable industrial population where one half the children die before they are five years old, the death rate is much less than among the young of the lion or the eagle. The average human death rate became much less in the nineteenth century than it had ever been before. The death rate in the world as a whole in 1911 is estimated to be 28.9 per thousand, which is far greater than that of the more advanced countries. The decrease in a quarter of a century in certain countries is as follows (for comparison with preceding table) :

 

Death

rate

 
 

1885

1912

Decrease

Australian Commonwealth .......... .....

15.7

10.7

5.0

Austria ........................

30.1

20.6

9.5

United Kingdom ..........................

19.4

13.8

5.6

France ..........................

22.2

17.5

4.7

German Empire ....................

25.3

15.6

9.7

Hungry .......................

33.1

23.3

9.8

Netherlands ...........................

21.4

12.3

9.1

Denmark .......................

18.4

13.0

5.4

Norway ....................

17.2

13.4

3.8

Sweden .......................

17.5

14.2

3.3

Italy .............................. .........................

27.3

18.3

9.0

Spain .....................................

32.6

21.3

11.3

The estimates of world population indicate that the increase of numbers was at the greatest rate in the half century from 1830 to 1880 and that it is now much less. Population increased so rapidly that the limit of resources began to be felt. The pressure of population makes itself felt in various ways, and on various levels of national culture in Japan, India, Germany, the United States, and in almost all other lands.

§ 7. Population growth and intensive cultivation. Let us analyze the process of change when population is a dynamic factor. A growth of numbers disturbs an established equilibrium of cultivation on the extensive and intensive margins (see Chapter 12), changes the relation of the value of labor-services to land uses (and to all instrumental uses), and leads to new levels of adjustment. Real changes are, of course, always complex, and along with population-changes go changes in machinery, area, methods, use of fertilizers, etc. Our question is as to the effect of population-change in itself considered, other things being equal, and for simplicity is limited here to the case of staple food crops.

A population on an area varying in fertility would apply its labor to the best tract. This, in an earlier example (Chapter 15) would be A, where, by hypothesis, 10 days' labor produces 24 units. Wages would stand at the level of 2.4 bushels and rents would be nil. When the pressure of population requires that B should be cultivated, the wages on A would be 22 bushels and rent about 2 bushels. When cultivation moves to tracts C and D, rent arises successively on B and C. If each tract continued to be cultivated with the same amount of labor as before, the rent on A would be first 2, then 4, then 6 bushels when tract D first came under cultivation ; the rent on B would then be 4 bushels, and the rent on C, 2 bushels. (See Figure 59.)

But with each extension of the margin of cultivation there should occur increasing intensity of cultivation on the older tracts, so that the return to a unit of labor should be equal in the two uses. When labor will yield but 2.2 bushels on B, it will be applied on A as long as it yields as much as 2.2 bushels (not 2.4 as before). Then this would work out as to rents and wages (in bushels) as shown in the table. (The amount of increase of labor for intenser cultivation is arbitrarily assumed. It would vary in practice but always be more intense as cultivation extended.)