Public Opinion
Deﬁnition of public opinion
Measuring public opinion
How is public opinion formed?
• psychologically how public opinion is formed
How informed is the public?
• consequences of public opinion in different political processes
• importance of the public opinion
How responsive is the government to public opinion?
How responsive should we want the government to be to public opinion?
“Those opinions held by private persons which governments ﬁnd it prudent to heed.”--V.O.Key
Measuring Public Opinion
Political science terminology:
• Micro vs.macro
• micro-individual thinking
• macro-public as one singular entity
• Dynamic vs.static
-the role of public opinion
• static-one ﬁxed point in time
• dynamic-focus on how public opinion change over time and how does the change
affect political process
• draw a sample in a right way that accurately represents the entire population that we have
• your population can be any group of people that you care about
How to get reliable results?
• Randomness is critical
• randomness is the ﬁrst requirement
• Good sample size
• Ideally,at least 1200-1500 respondents
• after get pass 1500 the payoff starts to decline-cost/beneﬁt
Randomness Every item (or person) selected from a group (or population) should have an equal probability of
being selected in the sample.
• volunteerism problem-if you don't raise your hand I can't choose your hand; people
who raise their hand is different from people who do not raise their hand
• Every ﬁfth person?
pollster-a prior decided to exclude the forth people
• sitting practices-because your friend is sitting next to you she can't be chose
• Draw names out of a hat?
• if your paper is smaller you have little chance to get selected
• maybe I prefer to grab in the right side of the hat
Potential Measurement Problems
Lessons from the Literary Digest
• 1932–FDR vs.Hoover
-> sending people postcards to poll in car registration phone books
• 57% to 40%--popular vote
• 89% to 11%--electoral vote
-> see that worked,sending people postcards again
-> the Landon prediction got really wrong
-> if you don't have a car/phone you can't get selected and working class people
can't be selected.Wrongly representing.Flawed.
• 61% to 37%--popular vote
• 99% to 1%--electoral vote
• Landon only won 8 electoral votes (ME & VT)
• Need more than sheer numbers
• though you have big samples size you need to be random in the ﬁrst place-if
you have a bad sample the size will not mean