If the population increases but births remain constant, what data concept explains this change?

• A. Aging of the population.
• B. Net migration.
• C. Death rate decrease.
• D. Birth rate increase.

Answer: (B)

Net migration explains this change. When births stay the same, a population grows only if more people move in than move out. Net migration is the balance of in-migration minus out-migration, so a positive net migration increases the population even with constant birth numbers. Aging changes how many people are in different age groups, not the total size. A lower death rate would affect numbers too, but the scenario specifies constant births, so the driver here is movement of people. A higher birth rate would increase births, which isn’t the case.