But is it not too late to oppose a standard universal identifier? Is not the SSN already a de facto SUI? To answer these questions, we must first measure the SSN against the criteria for an SUI given above.
UNIQUENESS. The SSN is not a unique label. More than 4.2 million people, by the Social Security Administration's own estimates, have two or more SSNs. More serious, although much less prevalent, are the instances in which more than one person has been issued or uses the same SSN.4
PERMANENCE. The SSN is, in almost all cases, permanent for an individual throughout his life.
UBIQUITY. The SSN is nearly universal for adult Americans, much less so for those of high-school age and below.
AVAILABILITY. The SSN of an individual is readily verifiable by the Social Security Administration for some users, and not at all for others. It is regainable from the Social Security Administration by persons who have lost their cards and forgotten their numbers, but not immediately. An individual's SSN, however, is increasingly ascertainable from many sources other than the Social Security Administration.
INDISPENSABILITY. The incentives and requirements to report one's SSN correctly are growing, though in some contexts there are incentives to omit or falsify the number.
ARBITRARINESS. The SSN is not entirely arbitrary; the State of issuance is coded into the number.
BREVITY. The SSN with its nine digits is three places longer than an alpha-numeric label capable of numbering 500 million people without duplication, and two places longer than one that can accommodate 17 billion people. The SSN could therefore be shorter if it were alpha-numeric.
RELIABILITY. The SSN has no check-feature, and most randomly chosen nine-digit numbers cannot be distinguished from valid SSNs. It is thus particularly prone to undetectable errors of transcription and oral reporting.
By our definition, the SSN cannot fully qualify as an SUI; it only approximates one.
The SSN had its genesis, in accounting practice and was first known as the Social Security Account Number (SSAN). It was established to number accounts for the 26 million people with earnings from jobs covered by the Social Security Act of 1935. Income-maintenance benefits under the Act, though not payable until the retirement or death of a worker, were to be determined on the basis of his record of earnings. Each worker needed a uniquely identifiable account to which records of his earnings would be posted periodically. Since obviously many would have the same or similar names, it was decided to assign each a unique number to identify his account and assure an accurate record of earnings, which his employer would report both by name and account number.
Name and number were used because standard accounting practice had accustomed people to numbered accounts, and because the technology of the day, notably the punched card machine with its 80-column card, required a short numeric identifier for efficiently adding the records of new transactions to existing master-file records.
Nine digits were chosen to provide for future expansion. A check-feature was not provided because the technology of the day could not cope with it, and manual checking, though possible, was judged too timeconsuming to be feasible. The Social Security Administration has developed ingenious error-detection methods, and has improved them over the years to the point where it now neither needs nor desires a check- feature.5
Despite the deficiencies of the SSN for purposes other than those for which it was designed, its use is widespread and growing, even where its limitations are recognized. How did this come about? Why is the SSN now so widely used for purposes and in areas unrelated to the Social Security program?