Measures of Mortality and Migration

Death rate refers to the decrease in the size of the population. A declining death rate due to the modern scientific heath services and a constant birth rate have been the major causes of rapid population growth in Nepal.

Three measures that are commonly used to estimate mortality rates are as follows: -

1. Crude Death Rate (CDR)
2. Age-Specific Death Rate (ASDR)
3. Infant Mortality Rate (IMR)

1. Crude Death Rate(CDR)

Crude Death Rate is a simple measure of mortality. It gives the number of deaths occurring in a given population during a specified year per 1000 of the population at mid-year.

2. Age-Specific Death Rate(ASDR)

Death rates of infants (0-1 year), children of 1-5 years or may be of adults beyond 60+ years can be measured during a specific year in a given population per 1000 specified age groups in the population at midyear. So, the age-specific death rate is the rate of deaths occurring in a certain age group of people in a place within a year.

3. Infant Mortality Rate(IMR)

Infants are considered as the age group of 0-1-year-old. IMR measures the mortality rate prior to the age below one. The infant mortality rate is calculated as follows: -

Measures of migration

Migration is another process of demography and deals with the change in the size and composition of the population by migrating from one place to another. There are two types of migration. They are national and international migration. In both of these migrations, there are two ways of the flow of population inflow and outflow. People who flow-in from another place or country are called immigrants and those who flow out from their native place or country is emigrants.

Various measures of migration are as follows: -

1. In-Migration Rate
2. Out-Migration Rate
3. Net Migration Rate
4. Gross Migration Rate

1. In-MigrationRate

In-Migration Rate deals with the people coming into a place or a country.

2. Out-Migration Rate

Out-Migration Rate deals with the people leaving the place of origin within or outside the country.

3. Net MigrationRate

Net Migration Rate refers to the difference of migrants, i.e. in-migrants and out-migrants. In other words, net migration rate is the ratio of net migration and the mid-year population in a year per every thousand population of that place.

4. Gross MigrationRate

Gross Migration Rate deals with the measurement of the total volume of migration or population turnover a country or a place experiences in a particular year.