American Government Public Opinion Two Ways to Measure Public Opinion • Intensity—how strongly people feel. • Representativeness—how widespread a particular belief is held. Measuring the Intensity of Public Opinion • • • • • Ask your family and friends Count people at demonstrations Track communications to elected officials Count membership in interest groups Voluntary polls: www.vote.com Measuring the Intensity of Public Opinion • Before the advent of scientific polling: – Information supplied by editorials, pamphleteers, local leaders – Straw polls – These methods were badly biased Straw Polling • Literary Digest conducted “presidential preference poll” in 1936 • Mailed 10 million ballots to car owners and phone customers • Prediction: Alf Landon (R) would beat FDR • Actual outcome: FDR won by 20% Why the Discrepancy? • Sample was not representative of the voting population • Selection mechanism was correlated with voting preference – Cars and phones = luxuries (in the 1930s!) – People who owned these items were mostly Republicans Scientific Polling—A Representative Measure • A poll with fewer respondents can be much more accurate • Basic techniques: – Random sampling – Bigger sample = better (up to a point) • Sample size of 100 yields margin of error +/- 5% • Sample size of 1000 yields margin of +/- 3% Random Sampling in Action Final Gallup Presidential Poll vs. Actual Outcome Year 2004 2000 1996 1992 Party D R D R D R Reform D R Indep Final Gallup 49 49 45 47 52 41 7 44 37 14 Actual 48 51 48 48 49 41 8 43 38 19 Error +1 -2 -3 -1 +3 0 -1 +1 -1 -5 How Accurate are Opinion Polls? • Sampling error – Reflects random differences between sample and entire population • Systematic error – Ex: leading questions How is this question biased? Sierra Club: “Our nation is still blessed with millions of acres of public lands, including road-less wilderness areas, forests, and range lands. Land developers, loggers and mining and oil companies want to increase their operations on these public lands. Do you think these remaining pristine areas of your public lands should be protected from such exploitation?” How is this question biased? National Right to Work Committee (antilabor union): “Are you in favor of allowing construction union czars the power to shut down an entire construction site because of a dispute with a single contractor, thus forcing even more workers to knuckle under to union agents?” “Push Polls” in Presidential Nominating Contests • In 2000, voters in South Carolina were asked: "Would you be more likely or less likely to vote for John McCain for president if you knew he had fathered an illegitimate black child?" Uninformed Responses • Even well-intentioned pollsters can run into this problem • People feel obligated to give an answer • National Affairs Act Poll – "Some people say that the 1975 Public Affairs Act should be repealed. Do you agree or disagree with this idea?” Should We Ignore Public Opinion Entirely? • If large segments of the public: – Are politically ignorant – Hold inconsistent views, and – Can be manipulated by varying the words or context of questions • How can public opinion play its assigned role in democratic politics? Is Public Opinion Meaningful? • Yes—in the aggregate if not always at the individual level • The sum of the public’s attitudes is both stable and coherent Stability of Aggregate Public Opinion Opinion Responds to Changing Conditions Explaining Aggregate Stability • Measurement errors and random individual changes cancel each other out – The average remains the same if circumstances remain the same • Opinion leadership – Provides cues and information – Means for uninformed/inattentive to free ride • Let's say you're a politician who is trying to commission a poll to determine whether the public supports a new program to provide down payments for first-time car buyers. Let's assume 30 percent of the public plans to buy a first car and would support the program no matter what; 40 percent already owns a first car but would support the program if it doesn't cost more than a buck a month in additional taxes; and 30 percent thinks the roads are crowded enough as it is and would oppose the program no matter what. • Group 1: How would you design a public opinion question to maximize support for the program? • Group 2: How would you design a public opinion question to minimize support for the program? • Group 3: How would you design a public opinion question to minimize bias in either direction?