Answer: Tax Reform

In the spring of 1987, something rather mysterious happened. Over 7 million Americans, all children, simply vanished. Was it mass abductions? Cold war experiments gone wrong? Something even more sinister? Not by any stretch of the imagination.

The case of the vanishing children can be directly attributed to a small but significant tax reform instituted by the Internal Revenue Service. Starting with the 1987 filing, you had to provide a Social Security number for any dependent you claimed on your taxes. As a result of the change, the number of children claimed as dependents between 1986 and 1987 dropped by 7 million–far more than one would expect from the eldest of those dependents becoming adults.