Commentary on "a methodology for identifying married couples in medicare data"

Authors of an article appearing recently in Demography propose a retrospect ive method to identify husband-wife pairs in administrative records. Althou gh their premise is correct, they overstate the power of their methodology. The error stems from a misunderstanding of how persons entitled to both pr imary and secondary social security benefits are classified in program data . A retrospective look four years after the reference date shows that the n umber of pairs is increased by less than 10%, not by more than 50%, as the authors claim.