The growth of the population is the sum of two indicators - natural and migration increase. Is the difference between the current level of the demographic situation and the level of the earlier period. The length of time over which the calculation is performed is called settlement and can be short-term (from one month to several years) and long-term (5, 10, 15, 25, 100 years).
Natural increase - the positive difference between the number of births and deaths (the number of births is greater than the number of deaths). For example, in Russia, according to the August 2009 born of 151.7 thousand people died 150,7 thousand people, so a natural increase of the population amounted to a thousand people. It is believed that if the birth rate exceeds the death rate, the reproduction of the population expanded. If these numbers are approximately equal, simple reproduction. If the death rate exceeds the birth rate, reproduction is narrowed, there is a strong demographic decline.
Migration (or mechanical) increase of the positive difference between the number of arrivals in a country of people from other countries and the number of departures from it citizens.
To determine the General pattern of demographic change in country coefficients of growth of the population. The rate of natural increase is the difference between the number of births and deaths over a period divided by the total number of the population. The migration growth of the population is the difference between the number of arrivals to the country citizens and the number of emigrants divided by total population. Accordingly, the overall rate of growth of the population is the sum of these coefficients.
Population growth is generally measured in percentage, so the resulting ratio is multiplied by 100. The total population is taken at the beginning of the billing period.
Based on the data and analysis population growth rate can predict the development of the situation in the coming periods.
Advice 2: How to calculate absolute increase
To determine the intensity of changes in any of the indicators over a certain period of time is used set of characteristics, which are obtained by comparing several levels of indicators measured on different levels of the timeline. Depending on how it compares measured values between obtained characteristics are referred to as growth coefficient, growth rate, growth rate, absolute increase, or an absolute value of 1% growth.
Determine what kind of indicators and how it is necessary to compare among themselves to obtain the desired value of the absolute gain. Assume that this feature should show the absolute rate of change of the studied indicator, and calculated as the difference between the current level and the level taken for the base.
Subtract from the current value of the examined indicator of its value measured at the point of the timeline, which is taken as the base. For example, assume that the number of workers employed in manufacturing at the beginning of this month is 1549, and at the beginning of the year, which is considered the reference period, it was equal to 1200 employees. In this case, the absolute increase for the period from the beginning of the year at the beginning of the current month amounted to 349 units, as 1549-1200=349.
If you not only need to calculate this figure for the last one period, but also to determine the average value of the absolute growth for several periods, it is necessary to calculate this value for each time stamp in relation to the previous one, then add up the values and divide them by the number of periods. For example, suppose you want to calculate the average value of the absolute increase in the number employed for the production of staff months of the current year. In this case, subtract the value of the indicator at the beginning of February, the appropriate value for the beginning of January, then do the same operation for couples March/February, April/March, etc. After this, add these values and divide the result by the sequence number of the last involved in the calculation of the months of the year.