Rate of natural increase
This article describes a ratio measure. In the standard operationalization, the numerator of the measure is natural increase (view other ratio measures with this numerator) and the denominator of the measure is population (view other ratio measures with this denominator). The denominator used for reporting is 1000. The measurement period is a year.
The denominator counts the total count of some type of entity, and an appropriate convention is set regarding the time within the measurement period that this count is calculated.
The Rate of natural increase (RNI) for a population in a given year can be defined in the following equivalent ways:
- It is the ratio of natural increase in that year (i.e., natural change measured so that increase is signed positive) to population, with the denominator scaled to 1000.
- It is the difference: crude birth rate - crude death rate, both measured for that population for that year.
Note that the term natural here signifies that the effects of migration are not being considered. In order to account for migration, we would add the net migration rate and obtain the population growth rate.