Mortality Measurement at Advanced Ages: A Study of the Social Security Administration Death Master File

Area of Science:

• Demography
• Gerontology
• Biostatistics

Background:

• Accurate mortality estimates at advanced ages are vital for population forecasts.
• Challenges include cohort heterogeneity, invalid hazard rate assumptions, and age exaggeration.
• Current methods of pooling international data fail to resolve heterogeneity issues.

Purpose of the Study:

• To propose and validate an alternative approach for estimating mortality hazard rates at extreme ages.
• To address issues of cohort heterogeneity and invalid standard assumptions in hazard rate estimation.
• To resolve age exaggeration problems in mortality data.

Main Methods:

• Utilizing data from the Social Security Administration Death Master File (DMF).
• Employing the method of extinct generations for single-year birth cohorts.
• Measuring hazard rates at narrow (monthly) age intervals using month of birth and death data.

Main Results:

• Mortality trajectory follows Gompertz law up to ages 102-105 without deceleration.
• Observed mortality deceleration below age 100 is an artifact of cohort mixing and cross-sectional data.
• Age exaggeration and crude assumptions contribute to underestimation of mortality at very advanced ages.

Conclusions:

• The proposed method resolves issues of cohort heterogeneity and invalid assumptions in hazard rate estimation.
• Mortality deceleration is not a biological phenomenon but an artifact of data aggregation.
• Accurate mortality estimates at advanced ages are achievable with homogeneous cohort data and monthly hazard rate analysis.