[albear]

What would be the reason for a population in a country (for example China) to decrease

(I didn't know what group to put this under)

[albear]

Any ideas

[NeedKarma]

China has strict rules concerning number of children per family.

[albear]

Thank you I already had that one I was wondering if anybody could think of any reasons I haven't got thank you though

[Clough]

Just another idea. If the country relied heavily on farming as means of income, and conditions became such that made it too difficult to farm anymore, the people might go somewhere else so that they could farm.

Here is another idea from the following site: Sounding Circle: Global Population Decrease?. I don't know whether it is correct or not. But, it is out there on the Internet.

Global Population Decerease?

There is indeed a population shortfall trend developing in Western Europe, Russia and Japan. In Ireland, for instance, families have an average of 1.8 children today, slightly below the "replacement level" of two children per couple. Couples in Italy, Germany and Spain have just 1.2 to 1.3 children each. The average fertility rate in Europe is 1.45. Both Russia and Japan are at 1.3. [/I]

Here is another idea found on European Population Decrease Explained. The referenced site and article below are from here: TCS Daily : Technology - Commerce - Society.

"Where Have All the Children Gone?

In the third century AD there was a prophet called Mani. He preached a doctrine of conflict between Good and Evil. He saw the material world as the devil's creation. Marriage and motherhood was a grave sin in his view, since by bearing children people multiply the works of Satan. The Manichean ideal was to move mankind to a superterrestrial realm of Good by way of gradual extinction.

In the course of history, Manichaeism was ruthlessly eradicated as an heretical, ungodly doctrine. When looking at demographic statistics, however, one might think that the populations in developed countries have converted en masse to Manichaeism and decided to become extinct. The birth rate in most western countries has fallen bellow replacement level.

In the so-called "New Europe", the situation is even gloomier. According to UN projections, Latvia will lose 44 percent of its population by 2050 as a result of demographic trends. In Estonia, the population is expected to shrink by 52 percent, in Bulgaria 36 percent, in Ukraine 35 percent, and in Russia 30 percent. In comparison with these figures, the projected population decline in Italy (22 percent), the Czech Republic (17 percent), Poland (15 percent) or Slovakia (8 percent) looks like a small decrease. France and Germany will lose relatively little population, and the population of the United Kingdom will even see a slight growth -- thanks to immigrants.

Why is the birth rate falling?

The question of why fertility has been falling so dramatically in continental Europe has been food for thought for both demographers and economists. The answer must be looked for in several important factors, which, to further complicate matters, do not simply add up in their impact. Nevertheless, it can be said with a fair amount of certainty that the existence of pay-as-you-go pension systems has had a very negative impact on birth rate. The National Report on Family published by the Czech Ministry of Labor and Social Affairs in August 2004 says:

"In terms of intergenerational solidarity, the importance of the child as
an investment for material support in old age has been limited by the
social security and pension insurance system, which has eliminated
people's immediate dependence on children. The importance of the child's
role in relation to its parents has transferred to the emotional sphere,
which reduced the direct material indispensability of children in a family,
while also allowing for them being replaced with certain substitutes
bringing emotional satisfaction."

To put it straightforwardly, and perhaps a little cynically, in the past children used to be regarded as investments that provided their parents with means of subsistence in old age. In Czech the word "vejminek" (a place in a farmhouse reserved for the farmer's old parents) is actually derived from a verb meaning "to stipulate": in the deed of transfer, the old farmer stipulated the conditions on which the farm was to be transferred to his son. Instead of an "intergenerational" policy, there used to be direct dependence of parents on their children. This meant that people had immediate economic motivation to have a sufficiently numerous and well-bred offspring - whereas today's anonymous system makes all workers pay for the pensions of all retirees in an utterly depersonalized manner.

This system enables huge numbers of "free riders" to receive more than what would correspond to their overall contribution in their productive life. Those with incomes way above the average, on the contrary, are penalized, as the system gives them less money than they contributed to it. This is referred to as the "solidarity principle". In terms of birth rate, this arrangement is discouraging for both the low-income group and the high-income one. The latter feel that they are not going to need children in the old age, while the former believe that they can't afford to have them.

Today, children no longer represent investments; instead, they have become pets - objects of luxury consumption. However, the pet market segment is very competitive. It is characteristic that the birth rate decline in the 1980s, and especially in the 1990s, was accompanied by soaring numbers of dog-owners in cities. While in the past dog-owners were predominantly retirees, today there are many young couples that have consciously decided to have a dog instead of a baby. These are mainly young professionals who have come to a conclusion (whether right or wrong) that they lack either time or money to have a child. Thus, they invest their emotional surpluses into animals.

Taxes are pivotal

State pensions systems eliminated the natural economic incentive to have children. At the same time, the welfare state is an enormously costly luxury that has to be financed from taxes. High payroll-tax and social security contributions reduce the earning capacity of people in fertile age. Thus, they push down birth rates as well.

A reader of the Wall Street Journal wrote in a letter on the issue:

"I am the son of a Pittsburgh steelworks worker. I was born at the end of
the Second World War. I have three sisters. Our mother never went to
work. After the experience of the Great Depression, our parents were
reluctant to borrow; yet they could afford to own a house, and our father
used to buy a new car once every three or four years. My parents
paid for my university education and bought me my first car when I was
twenty. We were by all standards part of the middle class, and I was proud
of my parents' achievement. (...) Today both my parents have to go to work
in order to maintain a middle-class living standard, due to the increase
in taxation that has occurred in the past half-century. (...) This has
produced a generation of children carrying a key around their necks,
city gangs, and aggressive brats brought up by after-school child-care
centers."

The tax burden in the United Stated has indeed grown significantly over the past 50 years. The birth rate has been falling proportionately, although not to the critical level that is now current in Europe. The birth rate in the US is nearing the replacement level -- about two children per woman. Even so, comparing to Europe, the United States still appears to be a confirmed and stable superpower.

"Even if we include immigration, the population of the original EU-12 will
fall by 7.5 million over the next 45 years, according to the UN calculations.
Since the times of the 'Black Death' epidemic in the fourteenth century,
Europe has never seen such an extensive population decline," writes
Niall Ferguson, a British historian. He also predicts that in 2000-2050,
the US population will grow by 44 percent. It seems that the European
Union will have to forget for good about its ambitious dreams of becoming
a "counterbalance" to America.

The demographic trends in Europe are indeed worrying. In Italy, for instance, the birth rate has fallen to an average level of 1.2 children per woman. Why? A journalist from the Daily Telegraph describes the life of young Italians in the following terms:

"It is virtually impossible to make a living. Just take Rome. Life with a
minimum of human dignity (a small rented apartment, occasional dinner in
a restaurant) requires a monthly pay of 3,000 euros before taxation,
which accounts for some 1,800 euros after tax. If in the Anglo-Saxon
world a majority of adults is expected to live an independent life on their
own salaries, in Italy this is often not the case. An incredible 70 percent of
unmarried Italians aged between 25 and 29 live with their parents, where they
benefit from subsidized housing and where their poor incomes amount to
a handsome pocket money."

When a modern young European has to choose between setting up a family of his own and a comfortable life without children, he is very likely to pick the latter option -- unless he belongs to a social class which regards children chiefly as a source of social benefits. A high amount of taxation combined with ill-functioning labor and housing markets is a truly genocidal mix."

The article continues, but was too long to place here as part of an answer.