Demography Population trends in history – The demographic transition Contemporary demography – The rich and poor world divide Implications of demography for society Population trends in history For most of human history on earth, the population was stable at about ten million people or so It did not start to rise until about 8000 BC and reached about 500 million in 1650 In 1650 it began to rapidly increase Why did that happen? Before 1650 mortality and fertility rates were both high. Since 1650, mortality rates fell but fertility stayed high – hence the increase in population. Today world population stands at 6.8 billion people So why did mortality start to decline in 1650? Decline of infectious diseases – typhoid fever, diphtheria, scarlet fever, TB, dysentery, typhus. Great reductions in mortality among the young. Why? Improvements in Public Health Better public health – especially cleaner water (without added sewerage) Better practices at home – use of toilets! Agricultural production increased in western Europe after 1650, and that meant more food for people and for livestock. Better nutrition – more meat, vegetables. Plus better practices at home… Hand washing before eating Clothes washing – helped by introduction of cotton clothes Widespread use of soap in 19th century As a result, people got bigger… Increase in height and life expectancy among U.S. males Then something even stranger happened… People stopped having so many babies in the late 1800s in Europe, a little later in the U.S. Families started getting smaller Birth rate fell from 30-40 babies born per 1000 people before 1900 to 14.16 babies born per 1000 people in 2007 (U.S.) Photo of the Sociologist Kenneth Westhues German grandparents in 1896, posing with their first eight children in front of their antebellum American home The sociologists Joseph Whitmeyer and Rosemary Hopcroft and their family, December 2009 Why the decline in fertility? Industrialization meant more people working in industry not on farms Especially if work required literacy, children became more of a cost as they had to be sent to school rather than helping on the farm. Decline in child mortality meant that people did not have to have lots of children to make sure some survived. This entire process – the fall in death rates, followed later by the fall in birth rates, is called the demographic transition. Stages of the demographic transition Contemporary Demography Many non-European countries have gone through a demographic transition in the last 50 years. Fertility is now quite low in most of the world except Africa. Countries that have high fertility rates contribute disproportionately to the growth in world population. The rich and poor world divide In poor countries, men can expect to live until they are 63.5 years old, women can expect to live until they are 67.5 In rich countries, men can expect to live until they are 73.5 and women until they are age 80. People in poor countries are most likely to die of infectious diseases, people in rich countries are most likely to die of heart disease and cancer. A population pyramid shows the number of people in different age and sex groups in a population Population pyramids in poor countries look like pyramids Population pyramids in rich countries look like posts Implications of demography for society A young society works very differently to an old society. Many young people mean many jobs catering to the young (e.g. education) Many old people mean many jobs catering to the elderly (e.g. nursing homes) The U.S. had a fairly youthful population in the 1950s and 1960s due to the baby boom. As the baby boomers age and retire beginning in 2010, there will be a large group of elderly people in U.S. society This is likely to strain programs for the elderly such as Social Security and Medicare Other implications of demography… Age and sex structure is also important in small groups such as workplaces Groups where the average age is younger operate differently to groups where the average age is older Population growth can have adverse effects on the environment It is a concern for the world, because we do not know how many people, at what standard of living, the world can bear. Immigration tends to bring people from poor countries into rich countries Generally this is not a problem in good economic times In bad economic times, anti- immigration sentiment is the likely result Demography and the democratic process In any democracy, any group that is in the majority tends to dominate the democratic process E.g. large numbers of older people generally mean that politicians pay attention to policies that benefit the aged.