Mortality was measured using Social Security Administration (SSA) death records. Total deaths in the SSA data closely match data from the National Center for Health Statistics (NCHS), with correlations exceeding 0.98 across ages and years (part I of the eAppendix, eFigure 1, and eTable 1 in the Supplement). Observations with income of $0 were excluded because the SSA does not fully track deaths of nonresidents, and thus mortality rates for individuals with income of $0 are mismeasured or unavailable. After excluding observations with income of $0, individuals were assigned percentile ranks from 1 to 100 based on their household earnings relative to all other individuals of the same sex and age in the United States during each year.

This is an amazing analysis, don’t get me wrong. But exactly how does one go about getting tax records for every individual in the US for every year from 1999 through 2014? How does one get the SSA to turn over the records of every individual with a valid SSN between 1999 and 2014? I wouldn’t even know where to start.

Sometimes studies like these are completely dependent on one’s ability and influence to get the data from the organizations that house it. We never talk about that. No one shares their secrets. Studies like this are, therefore, rare.

@aaronecarroll