Draft lottery (1969)
On
December 1,
1969, the
Selective Service System of the
United States held a
lottery to determine the order of
draft (induction) into the U.S. Army.
The days of the year, from 1 to 366, were written on slips of paper and the slips were placed in plastic capsules. The capsules were mixed in a shoebox and then dumped into a deep glass jar. Capsules were drawn from the jar one at a time.
The first number drawn was 258 (
September 14). Men of draft age whose birthday fell on the corresponding day of the year would all be drafted at the same time.
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1969 draft lottery scatterplot. A scatterplot of the days of the year (horizontal axis) and their ranks (vertical axis) shows a noticeable absence of days in December with high ranks (later induction). |
A secondary lottery was also held on the same day, to construct a random permutation of the 26 letters of the alphabet. For men born on a given day, the order of induction was determined by the rank of the first letters of their last, first, and middle names. [
1]
It was quickly noticed that draft ranks were not uniformly distributed over the year. In particular, birthdays in December had lower (earlier) draft ranks, on average, than birthdays in other months. This led to complaints that the lottery was not fair. Analysis of the lottery method suggested that the procedure (mixing the capsules in the shoe box and dumping them into the jar) did not mix the capsules sufficiently. The lottery system was later modified to make it more fair. The draft itself was suspended in 1973.
* D.E. Rosenbaum. "Statisticians Charge Draft Lottery Was Not Random," New York Times, January 4, 1970, p. 66.
* S.E. Fienberg. "Randomization and Social Affairs: The 1970 Draft Lottery".
Science, volume 171, pages 255-261 (1971).
(Cited by Starr as the "best and most comprehensive" article on the topic)* Norton Starr. "Nonrandom Risk: The 1970 Draft Lottery".
Journal of Statistics Education, volume 5, number 2 (1997).
(Also available on-line: [2] Contains a lesson plan for statistics class using the 1970 and 1971 draft lottery data)*
The Military Draft and 1969 Draft Lottery for the Vietnam War (News stories from the period)*
Introduction to Graphs (List of draft ranks, additional analysis)*
Frank Asaro - Astroid Impacts: The Inside Story (Mentions the shoebox in passing)
