Birth rate is commonly used to calculate population growth. It is combined with death rates and migration rates to calculate population growth so that over and under population records can be noted. AnswerParty!
Population ecology is a sub-field of ecology that deals with the dynamics of species populations and how these populations interact with the environment. It is the study of how the population sizes of species living together in groups change over time and space.
The development of population ecology owes much to demography and actuarial life tables. Population ecology is important in conservation biology, especially in the development of population viability analysis (PVA) which makes it possible to predict the long-term probability of a species persisting in a given habitat patch, such as a national park. Although population ecology is a subfield of biology, it provides interesting problems for mathematicians and statisticians who work in population dynamics.
Demographic economics or population economics is the application of economic analysis to demography, the study of human populations, including size, growth, density, distribution, and vital statistics.
Aspects of the subject include
The birth rate is the total number of births per 1000 of a population each year. The rate of births in a population is calculated in several ways: live births from a universal registration system for births, deaths, and marriages; population counts from a census, and estimation through specialized demographic techniques. The birth rate (along with mortality and migration rate) are used to calculate population growth.
The crude birth rate is the number of births per 1,000 people per year. Another term used interchangeably with birth rate is natality. When the crude death rate is subtracted from the crude birth rate, the result is the rate of natural increase (RNI). This is equal to the rate of population change (excluding migration).
Maximum sustainable yield
Population growth is the change in a population over time, and can be quantified as the change in the number of individuals of any species in a population using "per unit time" for measurement. In biology, the term population growth is likely to refer to any known organism, but this article deals mostly with the application of the term to human populations in demography.
Population growth rates might have declined, but in 2013 every 60 minutes there are another 8,000 people in the world: about 75 million every year.
In population ecology and economics, maximum sustainable yield or MSY is theoretically, the largest yield (or catch) that can be taken from a species' stock over an indefinite period. Fundamental to the notion of sustainable harvest, the concept of MSY aims to maintain the population size at the point of maximum growth rate by harvesting the individuals that would normally be added to the population, allowing the population to continue to be productive indefinitely. Under the assumption of logistic growth, resource limitation does not constrain individuals’ reproductive rates when populations are small, but because there are few individuals, the overall yield is small. At intermediate population densities, also represented by half the carrying capacity, individuals are able to breed to their maximum rate. At this point, called the maximum sustainable yield, there is a surplus of individuals that can be harvested because growth of the population is at its maximum point due to the large number of reproducing individuals. Above this point, density dependent factors increasingly limit breeding until the population reaches carrying capacity. At this point, there are no surplus individuals to be harvested and yield drops to zero. The maximum sustainable yield is usually higher than the optimum sustainable yield and maximum economic yield.
MSY is extensively used for fisheries management. Unlike the logistic (Schaefer) model, MSY has been refined in most modern fisheries models and occurs at around 30% of the unexploited population size. This fraction differs among populations depending on the life history of the species and the age-specific selectivity of the fishing method.
Population decline can refer to the decline in population of any organism, but this article refers to population decline in humans. It is a term usually used to describe any great reduction in a human population. It can be used to refer to long-term demographic trends, as in urban decay, white flight or rural flight, but it is also commonly employed to describe large reductions in population due to violence, disease, or other catastrophes.
A social issue (also called a social problem or a social situation) is an issue that relates to society's perception of a person's personal lives. Different cultures have different perceptions and what may be "normal" behavior in one society may be a significant social issue in another society. Social issues are distinguished from economic issues. Some issues have both social and economic aspects, such as immigration. There are also issues that don't fall into either category, such as wars.
Thomas Paine, in Rights of Man and Common Sense, addresses man's duty to "allow the same rights to others as we allow ourselves". The failure to do so causes the birth of a social issue.
Finance is the allocation of assets and liabilities over time under conditions of certainty and uncertainty. A key point in finance is the time value of money, which states that a unit of currency today is worth more than the same unit of currency tomorrow. Finance aims to price assets based on their risk level, and expected rate of return. Finance can be broken into three different sub categories: public finance, corporate finance and personal finance.