The world population has more than doubled in the last half a century – from 3.7 billion in 1970 to 7.8 billion in 2020. This rapid growth can largely be attributed to advancements in healthcare and medicine that have led to historically low death rates across much of the world. While the birth rates have also steadily declined in some countries, they have remained relatively high in many others, resulting in large population increases in several parts of the world.  

Although the global population as a whole has accelerated in recent decades, there is a marked contrast in the pace of population growth among countries and regions. Let us analyze the world population growth in the last 50 years with regard to geographical regions, income classifications, and demographic dividend.

Population Growth by Geographical Regions

Among the various geographic regions, Sub-Saharan Africa has experienced the greatest rise in population. The total regional population increased from 291 million in 1970 to 1.1 billion in 2020, representing a 281% increase over this period. As per the World Bank categorization, Sub-Saharan Africa includes all African countries other than those in North Africa. Many countries in this region, such as Nigeria and Ethiopia, are continuing to experience a high growth in population.

Sub-Saharan Africa is followed by the Middle East and North Africa (MENA) region whose number of residents grew by 230% (from 138 million in 1970 to 457 million in 2020). Egypt and Iran are among the most populated countries in MENA. However, the high population growth rate can partly be attributed to Saudi Arabia and other Gulf States experiencing a massive influx of foreign workers over the past few decades. On the other hand, countries in Europe & Central Asia have experienced the lowest rates of population growth in the past 50 years. The region’s total population stood at 738 million in 1970; it grew by a mere 25% over this period to 921 million by 2020.

Population Growth by Income Classification

The World Bank classifies countries, based on their gross domestic capital (GDP) per capita, into high income, upper-middle income, lower-middle income, and low income countries. The low income countries have experienced the highest population growth of 266% over the 50-year period (from 183 million to 669 million). Most of these countries are located in Africa where fertility rates are still quite high, combined with lower death rates than in the past. The low income group includes countries with an annual GDP per capita of $1,035 or less. DR Congo, Somalia, Ethiopia, Central African Republic, and Syria are some of the countries in the group.

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The next fastest population growth has been witnessed in the lower-middle income and upper-middle income groups respectively. The countries in the lower-middle income group have an annual GDP per capita between $1,036 and $4,045. The group includes Philippines, Vietnam, India, Nigeria, and Kenya, among other countries. The upper-middle income group (per capita GDP between $4,046 and $12,535) consists of 56 countries, including Russia, Turkey, Brazil, Mexico, Venezuela, Iran, Indonesia, and South Africa. The least population growth has been prevalent in high income countries (per capita GDP of $12,536 or more), located mainly in Europe, North America, the Gulf, and East Asia. Hence, there has been a strong inverse relationship between per capita income and population growth.   

Population Growth by Demographic Dividend

Demographic dividend refers to potential economic growth resulting from a change in the age structure of the population. This usually occurs when a greater proportion of the population falls in the working age (15 to 64 years) group. This results in a boost in working population productivity, thus creating a demographic “dividend” or benefit for the country. The World Bank categories countries into four stages: pre-demographic, early-demographic, late-demographic, and post-demographic dividend.

The pre-demographic dividend countries experienced the greatest population growth rate. The combined population of these countries increased by 295% between 1970 and 2020. On the other hand, the population of the post-demographic countries increased only 32% during the 50-year horizon. Again, this corresponds to the level of development in a country, where developed nations tend to have more mature populations, thus falling in the post-demographic dividend category. The less developed countries, in contrast, have not yet undergone the population age transition, and tend to have much younger populations.

To conclude, countries that have experienced the greatest population increase in the last 50 years tend to be low income, Sub-Saharan African, and pre-demographic dividend. These countries are usually the least developed ones, indicating that many more people are potentially born into poverty than ever before. Although there are large income gaps even within low income countries, and income levels are generally rising around the world, the unprecedented population growth in the poorest countries can act as an obstacle to poverty alleviation efforts.