1. The Dangers of Drawing Cohort Profiles From Period Data: A Research Note.
- Author
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van Raalte AA, Basellini U, Camarda CG, Nepomuceno MR, and Myrskylä M
- Subjects
- Humans, Forecasting, Population Dynamics, Fertility, Life Expectancy, Mortality
- Abstract
Drawing cohort profiles and cohort forecasts from grids of age-period data is common practice in demography. In this research note, we (1) show how demographic measures artificially fluctuate when calculated from the diagonals of age-period rates because of timing and cohort-size bias, (2) estimate the magnitude of these biases, and (3) illustrate how prediction intervals for cohort indicators of mortality may become implausible when drawn from Lee-Carter methods and age-period grids. These biases are surprisingly large, even when the cohort profiles are created from single-age, single-year period data. The danger is that we overinterpret deviations from expected trends that were induced by our own data manipulation., (Copyright © 2023 The Authors.)
- Published
- 2023
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