In 2010 well over 200 million international migrants live around the globe, most seeking better economic opportunities, though others also fleeing conflicts, or repressive or ineffectual governments, in their home countries. While the USA is the single country with the largest number of international immigrants (43 million), there are even larger numbers of migrants in total living in both Europe and Asian. A number of interrelated economic, social, political, and ethical issues are associated with international migration, many of which are far from being resolved - or, in some cases, even either recognized or accepted by large numbers of people in receiving countries.

The article outlines the scope and nature of forced displacement in Sub-Saharan Africa. Beginning by situating African refugee populations within the global geography of refugees, I trace out the regional variation of displacement within Sub-Saharan Africa. I also outline the major legal and historical documents guiding the treatment and definition of African refugees. In conclusion, I examine the challenges and opportunities facing African governments and communities as they continue to struggle with protracted forced displacement.

China’s stringent birth control policy and rapid economic growth have brought about significant demographic changes in recent decades. It is the only large developing country to have completed demographic transition. Its birth, death, and natural increase rates are very similar to those of developed countries. As the world’s most populous country gets a respite from rapid population growth, it finds itself embracing several other challenges. The Chinese population is aging. Meeting the needs of a large and growing elderly population will be a daunting task, given China’s current development level and weak social security system. The highly skewed sex ratio may have very troubling social repercussions. In the meantime, hundreds of millions of Chinese are on the move in search of “greener pastures.” The unprecedented internal migration is driving China’s rapid urbanization and reshaping its economy and society.

Latin America and the Caribbean is the most urbanized region in the world with approximately 69 % urban population in Middle America and the Caribbean and 81.6 % in South America. The hierarchy of cities reflects pre-Hispanic and colonial settlement patterns and modern transportation routes. While the largest metropolitan regions continue to increase in size and population, the greatest change is occurring in the small and medium size cities.

Brazil is a continent-sized county, with a great diversity of ecosystems, unequally transformed by the processes of occupation and territorial formation. In the southern half of the country, the natural environment has been replaced by a humanized natural environment due to the pushing back of settlement frontiers, which, for five centuries, has transformed Brazil’s land use. In recent decades the rhythm of change has been faster: on one hand, the population has increased, and migrated to the cities; on the other hand, the cultivation of major crops (coffee, sugar, soybean, cotton, etc.) has moved northwards and westwards, reaching northern regions such as Mato Grosso and Pará, threatening the rainforest in the Amazon Basin.

Historical, political and economic factors have had a profound effect on the origins, destinations, permanence, selectivity, and adjustment problems of Mexican migrants to the United States. At the turn of the 20th century, the U.S. industrial revolution coupled with the Mexican Revolution created the respective pull and push forces to stimulate large-scale Mexican migration which received further stimuli from labor demands in the USA after 1940 and Mexican economic crises after 1970. At the turn of the 21st century, regional and class inequalities in Mexico stemming from neo-liberal policies have stimulated migration anew, especially from southern Mexico. Regional economic restructuring in the USA has simultaneously generated new flows of Mexican labor into the Southeast and Midwest. However, events after 2000 have led to unilateral border militarization by the U.S. government. Mexican migrants have in a real sense been “walled in", forcing them into a marginal existence in the USA. As their wages and employment have dropped, their remittances to Mexico have declined. Mexican migrant villages are de-populating and their residents moving permanently to the U.S. or to Mexican cities.

Population ageing will be the most dominant demographic challenge confronting the European Union in the 21st century and will affect everybody. Sustained low fertility and increasing longevity will speed up population ageing in the coming decades. The currently observed East-West division, which is based on more pronounced ageing in the West, will reverse and intensify in the future. The amount of replacement migration that would be necessary to counterbalance expected population declines would be much larger than the net migration observed today and therefore can only moderate population ageing. Using people's "prospective age" as the basis for estimating their remaining life span, the future population ageing scenario will be slower, and we will observe considerably lower values of the old-age dependency ratio. Population ageing, despite its apparently negative connotations, should be seen as a human achievement because of an enormous decrease in mortality and improvement in health.

The second half of the twentieth century was a period of substantial improvements in health among the populations in both developed and developing countries which completely bypassed the countries of the former Soviet Union. Aside from an anti-alcohol campaign in the mid-1980s, the highest life expectancy achieved by the population of Russia was in 1964. Extremely high rates of alcohol and tobacco consumption are to blame for the low levels of life expectancy in Russia and several other states of the former Soviet Union and contribute to Russia having the largest difference in life expectancy between males and females in the world. The continued population decline in Russia will begin to have an impact on economic growth.