In the context of the outbreak of the first World War, the alliance between France and Russia played a vital role. Although this stems from the mutual political loyalty between France and Russia, it is also acknowledged that this was because France was losing the population race with Germany at that time, thus promoting the alliance between France and Russia. France provided Russia with capital and technology in exchange for Russia’s huge human resource reserves. The rise of multicultural society in Britain in the 21st century has made it get rid of the problem of the decline of population replacement ability in the second half of the 20th century. This encouraged the exchange of migrant labor and capital transfer from the former British colonies. Japan’s early economic success can be partly explained by its high density of population, which makes technology transfer possible. The political alliance, cultural change and economic growth of the countries concerned can be attributed in part to the demographic structure of these countries< IMG ALT = "demography, written by Sarah Harper, translated by Xu liming, Yilin publishing house, 2022 edition" style = "width: 600px;" src=" https://imagecloud.thepaper.cn/thepaper/image/210/931/975.jpg ">
demography, written by Sarah Harper, translated by Xu liming, Yilin publishing house, 2022 < / P > the origin of the concept of” population is destiny “is controversial. Although few people adhere to this deterministic position, people are increasingly aware that population change plays a key role in the political system, economy and society at the local, national, regional and global levels. < br > < div class =" height "> < / div "Human" interests, such as anthropology, sociology and psychology. However, the core concept of demography is the driving factors of population change, namely, death, fertility and population migration, and how these factors interact to affect the population. The interaction of these population drivers has led to various results in terms of population size, composition, density and distribution. These results will vary within and among countries and regions, and then have a significant impact on the societies and communities they form and the individuals who constitute these societies and communities< Br > < div class = "height" > < / div > for example, the birth cohort or generation of each person, the population composition of the cohort and its relationship with those who were born in other places at the same time, as well as those who were born before and after, strongly affect the life opportunities of individuals. In addition, it will also affect the economic and political structure in which people live, and construct people’s access to social and natural resources such as food, water, education, work, sexual partners and even personal life< Br > < div class = "height" > < / div > England in the middle of the 17th century was in an era of Renaissance and discovery, and also an era of plague and death. The coincidence of these two conditions led to the emergence of demography. The Royal Society of England was founded in 1660, dedicated to “empirical observation and experiment”; Newton and his colleagues at Cambridge University were developing calculus, mechanics and gravitational theory. Identifying mathematical formulas that can explain God’s masterpieces in physics and the physical world is a natural way to find more formulas that can explain God’s human body plan< Br > < div class = "height" > < / div > the continuous spread of the plague makes death spread around. The death list, which publishes the number of London funerals every week, provides a perfect source for exploring the laws of life and death that God made when he created the world. Businessman John grunt used these data to make the first original life table in 1662, which was one of the initial research contents of demography. So far, the mathematical laws of life and death have been added to the laws of the earth, the sea and the sky. Although over the centuries, demography has developed into a theory and methodology that covers a wide range of basic principles such as population growth, reproduction and change, it still keeps exploring the mathematical laws that can explain the length of human life in its core; This search has now become a research field shared by demographers and their counterparts in mathematics, evolutionary biology and genetics< Br > < div class = "height" > < / div > contemporary demography can be divided into three independent research fields: < br > < div class = "height" > < / div > first, it is to study the past or present characteristics of population size and composition, and is particularly interested in age, gender, marital status, education level, spatial distribution, race and socioeconomic groups< Br > < div class = "height" > < / div > secondly, it is interested in various processes that directly affect the population composition, mainly fertility, death and population migration, sometimes referred to as population driving factors< Br > < div class = "height" > < / div > the third field concerns the relationship between these static characteristics and dynamic processes, as well as their mutual influence in the social, economic and cultural environment< Br > < div class = "height" > < / div > contemporary authors believe that modern demography occupies a special position in social science. Unlike many other social disciplines (such as sociology or Psychology), the analysis object of demography is very clear, that is, people. Moreover, the laws of human behavior that determine the main population processes – reproduction and death, or fertility and death – are more regular than many other human behavior processes. Third, contemporary demography is a truly interdisciplinary discipline, because it relies to a large extent on other social sciences to interpret demographic results< Br > < div class = "height" > < / div > in this book, I will first discuss the evolution of the global population in time and space. It has experienced a stable but small growth in several thousand years, and it began to change to a rapid growth about 200 years ago. At the end of the last ice age 20000 years ago, an estimated 1 million Homo sapiens were scattered in Europe, Africa and Asia. In the next 15000 years, with the emergence of agriculture, settlement life and civilization, great changes have taken place in human economy and society. By 5000 BC, the world’s population was estimated to have reached 5 million, and human beings had settled on every continent. After another 7000 years, about 1800, the population reached 1 billion< Br > < div class = "height" > < / div > the arrival of urbanization and industrialization has led to a steady increase in population. Since 1700, the mortality rate has started a long-term gradual decline process: the trade, agricultural and industrial revolutions have improved the living standards, and public health measures have greatly reduced the infant and child mortality rates. By the early 20th century (around 1930), the population had doubled to 2 billion; It has doubled in 50 years, reaching 4 billion (1975); By the end of the 20th century, it had reached 6 billion. At present, this figure is about 7 billion, and it is expected to reach about 10 billion in the 21st century< Br > < div class = "height" > < / div > then, I will focus on the development of the subject of demography. I will count the main theorists, what makes them interested in demography, and how they have shaped the subject in the past few centuries. As I have described, the formal study of demography can be traced back to the original life table of grunt in the mid-17th century. Others took over the task, and by the 19th century, mathematical estimation was already complex and highly recognized. Theoretically, it is Malthus who put forward the hypothesis that unlimited population growth may have an impact, so he is regarded by many as the real founder of demographic research< Br > < div class = "height" > < / div > one of the main arguments revolves around population change. This refers to a series of changes that occur when a country evolves from a stable state of high mortality and high fertility to a stable state of low mortality and low fertility. Theorists have argued fiercely about the timing and driving factors of this transformation. We will explore the tools and materials that demographers use to understand these processes< Br > < div class = "height" > < / div > by the beginning of the 20th century, demography had been considered as a separate research field. For the first time, demography courses were taught in universities. Key theorists were recognized and developed a set of clear methods and technologies. In addition, we will also consider the emergence of new demographic sub disciplines. In recent decades, demography has been brought into the research field by other disciplines (such as sociology, history and Economics), and at the same time, a series of sub disciplines have been developed. Now, biological demography, population economics, population geography, social demography and human demography have all become part of the broad field of population research. These studies analyze the relationship between economic, social, cultural and biological processes that affect the population. This enables us to adopt a multidisciplinary approach, which can be used to solve various contemporary problems, and look forward to the future with the help of the prediction ability of demography< Br > < div class = "height" > < / div > do all countries have population policies? Before addressing some of the key demographic challenges of the 21st century, we will examine some of them. Will the fertility rate in sub Saharan Africa fall below the level of intergenerational replacement? If not, what will be the consequences? What is the relationship between environment, population and consumption in different parts of the world? How will we provide food and water for the 9 billion or 10 billion people projected to reach 2050? What will be the impact of the upcoming aging of the world population< Br > < div class = "height" > < / div > demography with mathematical science as its core is trying to solve some of the most important challenges. Population may not be fate, but it does provide the necessary scientific evidence to guide governments and policymakers across the 21st century< br>