Why Did Dewey Beat Truman in the Pre-election Polls of 1948?
On election night in 1948, like many other people, I attended to the media later and later, and finally about 1:30 a.m. I abandoned hope of a decision and went to bed. Next morning we found that Harry Truman had defeated Thomas Dewey for the presidency of the United States, contrary to all the media wisdom. More important from a statistical point of view, the media had been continuously and confidently informed by the various polling organizations (such as Crossley, Gallup, and Roper) that Dewey would be the winner. These events led to my participation in a large social science study of pre-election polling.
