Migration from a set of rates (cont.)

A rate for net migration?

Net migration can be defined as the difference between gross in-migration and gross out-migration. When comparing several time periods or areas the definitions should be standardized. The probability of out-migration should relate all migration streams to the population at area of origin. In-migration is not a usual rate and can be ambiguous as it refers to the area of destination.

Exercise

interaction What is an appropriate population at-risk for the in-migration of a specific region in a Country?

a) The population of the remainder of the Country at the beginning of the period
b) The population of the remainder of the Country at the end of the period
c) All the persons living in the destination area at the end of the time interval
d) The average of the population of the destination region and the remainder of the Country
Check your answer
Please select an answer Correct: That is the population exposed to risk of migration in the origin area. Wrong: The population exposed to the risk of migration was living in the origin area, but at the beginning of the period. Wrong. Remember: The non-migrant living in the destination at the end of the time interval can not be an in-migrant. Wrong: A rate like this would expresses the net stream as proportion of the average of their population – it is not to be considered as an  at-risk  rate.