Population decline

Population decline is the reduction over time in a region's census. It can be caused for several reasons; notable ones include sub-replacement fertility (along with limited immigration), heavy emigration, disease, famine, and war.

Prior to the 20th century, population decline was mostly observed due to disease. The Black Death in Europe, the arrival of Old World diseases to the Americas, the tse-tse fly invasion of the Waterberg Massif in South Africa, and the Great Irish Famine (1845–1849) have all caused sizable regional population declines. In modern times, the AIDS epidemic has caused declines in the population of some African countries. Less frequently, population declines are caused by genocide or mass execution; for example, in the 1970s, the population of Cambodia went through a period of decline due to wide scale executions by the Khmer Rouge regime.

According to recent reports by the United Nations Population Division and the US Census Bureau, population decline is occurring today in some regions. According to the UN, below-replacement fertility is expected in 75 per cent of developed world by the year 2050. The US Census Bureau notes that the 74 million people added to the world's population in 2002 were fewer than the high of 87 million people added in 1989-1990. The annual growth rate was 1.2 percent, down from the high of 2.2 percent in 1963-64.

"Census Bureau projections show this slow-down in population growth continuing into the foreseeable future," stated the Bureau's brief on the findings. "Census Bureau projections suggest that the level of fertility in many countries will drop below replacement level before 2050... In 1990 the world's women, on average, were giving birth to 3.3 children over their lifetimes. By 2002 the average was 2.6." Of course, this value still ensures the continuing rapid growth of the human population as a whole, even if some regions may decline.

Sometimes the term underpopulation is applied in the context of a specific economic system. It does not relate to carrying capacity, and is not a term in opposition to overpopulation, which deals with the total possible population that can be sustained by available food, water, sanitation and other infrastructure. "Underpopulation" is usually defined as a state in which a country's population has declined too much to support its current economic system. Thus the term has nothing to do with the biological aspects of carrying capacity, but is an artificial term employed to imply that the transfer payment schemes of some developed countries might fail once the population declines to a certain point. An example would be if retirees were supported through a social security system which does not invest savings, and then a large emigration movement occurred. In this case, the younger generation may not be able to support the older generation.

By specific countries
Today emigration and sub-replacement fertility rates that are principal issues related to any regional population decline. A number of nations today are experiencing population decline, stretching from North Asia (Japan) through to Eastern Europe through Russia including Kazakhstan, Ukraine, Belarus, Moldova, Estonia, Latvia, Lithuania, Bulgaria, Georgia, Armenia, Serbia, Bosnia, Croatia, Slovenia, and Hungary.

The population of former Soviet Republics, with the exception of Muslim majority nations and oil rich Azerbaijan, is falling due to health factors and low replacement. Much of Eastern Europe has lost population due to migration to Western Europe. In Eastern Europe and Russia, natality fell abruptly after the end of Communism. Together these nations occupy over 8 million square miles and are home to over 400 million people (less than six percent of the world population), but if current trends continue, more of the developed world and some of the developing world could join this trend.

Many nations in Western Europe today would have declining populations if it were not for international immigration. Some think that there will be underpopulation in Japan by 2014; Japan's situation is related to low replacement and an extremely low level of immigration.

AIDS plays some role in population decline; however, data available suggest that, even with high AIDS mortality, fertility rates in Africa are sufficiently high, so that overpopulation trends continue.

Economic consequences
The effects of a declining population can be adverse for an economy which has borrowed extensively for repayment by younger generations; however, a smaller human population has a positive impact on the environment and biodiversity. Problems associated with declining population are not irreversible or as severe as overpopulation.

Economically declining populations can lead to deflation, which has a number of effects. For an agricultural economy the average standard of living, at least in terms of material possessions, will tend to rise as the amount of land and resources per person will be higher. But for many industrial economies, the opposite can be true as those economies often thrive on mortgaging the future by way of social welfare and retirement transfer payments. However, standard of living does not necessarily correlate with quality of life, which may very well increase as the population declines (especially if the area in question is somewhat overpopulated to begin with).

The period immediately after the Black Death, for instance, was one of great prosperity, as people had inheritances from many different family members. However that situation was not comparable, as it did not have a continually declining population, but rather a sudden shock, followed by population increase. Predictions of the economic effects from a slow and continuous population decline (i.e. due to low fertility rates) are mainly theoretical since such a phenomenon is a relatively new and unprecedented one.

A declining population due to demographics will also be accompanied by population ageing which can contribute problems for a society. The decade long economic malaise of Japan and Germany is often linked to these demographic problems. The worst case scenario is a situation where the population falls to too low a level to support a current social welfare economic system, which is more likely to occur with a rapid decline than with a slower one.

However, the economies of both Japan and Germany both went into recovery around the time their populations just began to decline (2005). In other words, both the total and per capita GDP in both countries grew more rapidly than before 2005. Russia's economy also began to grow rapidly in the past few years, even though its population has been shrinking since 1992-93 (the decline is now acccelerating). In addition, many Eastern European countries have been experiencing similar effects to Russia. Such renewed growth calls into question the conventional wisdom that economic growth requires population growth, or that economic growth is impossible during a population decline.

A declining population (regardless of the cause) can also create a labor shortage, which can have a number of positive as well as negative effects. While some labor-intensive sectors of the economy may fail if the shortage is severe enough, others may adequately compensate by increased outsourcing and/or automation. On the positive side, such a shortage increases the demand for labor, which can potentially result in a reduced unemployment rate as well as higher wages (or a reduced underemployment rate).

A smaller national population can also have geo-strategic effects, but the correlation between population and power is a tenuous one, especially in today's world.

National efforts to reverse declining populations
"President Vladimir V. Putin directed Parliament on Wednesday to adopt a 10-year program to stop the sharp decline in Russia's population, principally by offering financial incentives and subsidies to encourage women to have children.", "Australia offers a $4,100 bonus for every baby plus additional fortnightly payments, a free immunization scheme and recently proposed to pay all child care costs for women who want to work. Many European countries, including France, Italy and Poland, have offered some combination of bonuses and monthly payments to families. Some Japanese localities, facing significant population loss, are offering economic incentives. Yamatsuri, a town of 7,000 just north of Tokyo, offers parents $4,600 for the birth of a child and $460 a year for 10 years. The Republic of Singapore has a particularly lavish plan: $3,000 for the first child, $9,000 in cash and savings for the second; and up to $18,000 each for the third and fourth."

Alternative concept relative to skills
Sometimes the concept of population decline is applied where there has been considerable ex-migration of skilled professionals. In such a case, the government may have ceased to reward or value certain skills (e.g. science, medicine and engineering), and sectors of the economy such as health care and technology may go into decline. Such characterizations have been made of Italy and Russia in the period starting about 1990.