Why do rates and measures of population change use the “total mid-year population” instead of the “end-of-year population?”

Paper details

Epidemiologists are concerned with population growth as it relates to potential healthcare issues. Why do rates and measures of population change use the “total mid-year population” instead of the “end-of-year population?” What makes one measurement more effective than the other? Choose a real or a hypothetical example to explain how using the “end-of-year population” affects data collection and outcomes.