A method for estimating year of birth using social security number

Area of Science:

• Epidemiology
• Demography
• Biostatistics

Background:

• Accurate demographic data, including birth year, is crucial for epidemiologic research.
• Missing birth dates in historical datasets pose a significant challenge for population studies.
• Existing methods for inferring birth year are often imprecise or require additional information.

Purpose of the Study:

• To develop and validate a method for estimating an individual's year of birth using only their Social Security number (SSN).
• To assess the accuracy and reliability of the proposed estimation method across different birth cohorts.
• To explore the utility of this method in overcoming data limitations in retrospective epidemiologic studies.

Main Methods:

• Estimating the year of Social Security number (SSN) issuance using Social Security Administration tables or extrapolation for pre-1951 numbers.
• Calculating age at SSN issuance based on a reference population with known birth dates and SSNs.
• Determining the estimated year of birth by subtracting the estimated age at issuance from the estimated year of issuance.

Main Results:

• A strong positive correlation (0.91) was observed between known and estimated years of birth.
• The method achieved predictions within +/- 5 years for 78% of the study population.
• For individuals born after 1934, 95% of predictions were within +/- 5 years, and 77% were within +/- 2 years.

Conclusions:

• The SSN-based method provides a statistically valid and accurate approach for estimating year of birth.
• This technique offers a practical solution for situations where birth dates are missing in epidemiologic research.
• The method's high accuracy, particularly for more recent birth cohorts, enhances its applicability in various research settings.