MPIDR Working Paper

Quality of reported ages: a robust re-modification in total modified Whipple’s index

Rasul, A., Nasir, J. A., Jasilionis, D., Jdanov, D. A.
MPIDR Working Paper WP-2023-043, 17 pages.
Rostock, Max Planck Institute for Demographic Research (November 2023)
Open Access


In demographic research, th accuracy of the reported ages in surveys and censuses is a persistently important issue. The common indexes developed and used to examine the quality of age data are Whipple, Myers, Bachi's, modified Whipple, and the total modified Whipple’s index. The most commonly used and simplest to compute index is the original Whipple's index proposed by George Chandler Whipple. It is a summary measure used to check age heaping on ages ending with digits 0 and 5. The other summary index is the total modified Whipple index (Wtot) by Spoorenberg (2007). A re-modification (RWtot) is proposed for the total modified Whipple index. The new modification, based on the method of the original Whipple index for all digits (0, 1, 2 … 9), is simple, robust, and easy to interpret. The proposed modification is suitable for social, temporal, and spatial comparisons of the quality of self-reported and interviewer-recorded ages at the time of surveys and censuses.

Key Words: Quality of reported ages, Whipple Index, Modified Whipple Index, Total Modified Whipple index

The Max Planck Institute for Demographic Research (MPIDR) in Rostock is one of the leading demographic research centers in the world. It's part of the Max Planck Society, the internationally renowned German research society.