Chapter 1.4, Problem 21E

Literary Digest poll: In the 1936 presidential election, Republican candidate Alf Landon challenged President Franklin Roosevelt. The Literary Digest magazine conducted a poll in which they mailed questionnaires to more than 10 million voters. The people who received the questionnaires were drawn from lists of automobile owners and people with telephones. The magazine received 2.3 million responses, and predicted that Landon would win the election in a landslide with 57% of the vote. In fact, Roosevelt won in a landslide with 62% of the vote. Soon afterward, the Literary Digest folded.

1. In 1936 most people did not own automobiles, and many did not have telephones. Explain how this could have caused the results of the poll to be mistaken.
2. What can be said about the response rate? Explain how this could have caused the results of the poll to be mistaken.
3. The Literary Digest believed that its poll would be accurate, because it received 2.3 million responses, which is a very large number. Explain how the poll could be wrong, even with such a large sample.