Births & Deaths

Natural increase occurs when births (fertility) exceed deaths (mortality). Various measures provide insights into different aspects of fertility and mortality.

Fertility

The crude birth rate (CBR) is the total number of live births in a year for every 1,000 people alive in the society. A CBR of 20 means that for every 1,000 people in a country, 20 babies are born over a one-year period.

The world map of CBR mirrors the distribution of NIR. As was the case with NIRs, the highest CBRs are in sub-Saharan Africa, and the lowest are in Europe. Many sub-Saharan African countries have a CBR over 35, whereas many European countries have a CBR below 10.

Crude Birth Rate (CBR), 2018

The global distribution of CBRs in 2018 parallels that of NIRs. The countries with the highest CBRs are concentrated in Africa and Southwest Asia.

The total fertility rate (TFR) measures the number of births in a society. The TFR is the average number of children a woman will have throughout her childbearing years (roughly ages 15 through 49). To compute the TFR, demographers assume that a woman reaching a particular age in the future will be just as likely to have a child as are women of that age today. Thus, the CBR provides a picture of a society as a whole in a given year, whereas the TFR attempts to predict the future behavior of individual women in a world of rapid cultural change.

Total Fertility Rate (TFR), 2018

As with NIRs and CBRs, the countries with the highest TFRs are concentrated in Africa and Southwest Asia.

The TFR for the world as a whole is 2.4, and, again, the figures vary between developed and developing countries. The TFR is 4.9 in sub-Saharan Africa, compared to 1.6 in Europe.

Mortality

The infant mortality rate (IMR) is the annual number of deaths of infants under one year of age, compared with total live births. The IMR is usually expressed as the number of deaths among infants per 1,000 births rather than as a percentage (per 100). In general, the IMR reflects the quality of a country’s health-care system.

Infant Mortality Rate (IMR), 2018

The highest IMRs in 2018 are in sub-Saharan Africa, and the lowest are in Europe.

The global distribution of IMRs follows the pattern that by now has become familiar. Lower IMRs are found in countries with well-trained doctors and nurses, modern hospitals, and large supplies of medicine. The IMR is 4 in Europe, compared with 54 in sub-Saharan Africa. In other words, before reaching their first birthday, 1 in 18 babies die in sub-Saharan Africa and 1 in 250 babies die in Europe.

The crude death rate (CDR) is the total number of deaths in a year for every 1,000 people alive in the society. As with the CBR and IMR, the CDR is expressed as the annual number of deaths per 1,000 population.

The CDR does not follow the same regional pattern as the NIR and CBR. The combined CDR for all developing countries is actually lower than the combined rate for all developed countries. Furthermore, the variation between the world’s highest and lowest CDRs is much less extreme than the variation in CBRs. The highest CDR in the world is 16 per 1,000, and the lowest is 1—a difference of 15—whereas CBRs for individual countries range from 7 per 1,000 to 48, a spread of 41. The CDR is 7 in developing countries and 10 in developed countries, whereas the CBR is 21 in developing countries and 10 in developed countries.

Crude Death Rate (CDR), 2018

The global pattern of CDRs in 2018 varies from those for the other demographic variables already mapped in this chapter. The demographic transition helps to explain the distinctive distribution of CDRs.

Why does Denmark, one of the world’s wealthiest countries, have a higher CDR than The Gambia, one of the poorest? Why does Germany, one of the world’s wealthiest countries with one of the world’s best health-care systems, have one of the world’s highest CDRs? The answer is that the populations of different countries are at various stages in an important process known as the demographic transition, discussed below.

Pause & Reflect 2.2.2

What region of the world appears to have the lowest CDR. What might account for that?