feb 2011 reuters ipsos qb poll topline (020312)

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  • 8/3/2019 Feb 2011 Reuters Ipsos QB Poll Topline (020312)

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    Interview dates: January 30-February 3, 2012

    Base: 2475 Americans

    Ipsos Poll conducted for Reuters, February 2012

    Quarterback Primary PollNOTE: all results shown are percentages unless otherwise labeled.

    These are findings from an Ipsos poll conducted for Thomson Reuters from January 30th

    February 3rd, 2012. For the survey, a

    sample of 2475 Americans was interviewed online. The precision of the Reuters/Ipsos online polls is measured using a credibility

    interval. In this case, the poll has a credibility interval of plus or minus 2.3 percentage points for all respondents. For more

    information about credibility intervals, please see the appendix.

    The data were weighted to the U.S. current population data by gender, age, education, ethnicity and a political values scale.

    Statistical margins of error are not applicable to online polls. All sample surveys and polls may be subject to other sources of

    error, including, but not limited to coverage error and measurement error. Figures marked by an asterisk (*) indicate a

    percentage value of greater than zero but less than one half of a per cent. Where figures do not sum to 100, this is due to the

    effects of rounding.

    QUARTERBACK PRIMARY POLL

    Q. If the age restriction did not exist and only quarterbacks in this years NFL playoffs were eligible to run for President of

    the United States, who would you vote for?(Select one)

    PARTY ID & REGION

    Total Democrat Republican Independent Northeast Midwest South West

    Tim Tebow 26 20 39 16 18 23 29 29

    Eli Manning 18 21 13 20 34 15 12 15

    Tom Brady 17 17 14 22 23 16 15 16

    Drew Brees 15 17 15 13 9 14 21 13

    Aaron Rodgers 7 7 8 8 5 18 3 6

    Ben Roethlisberger 4 5 4 3 5 4 4 4

    Joe Flacco 3 4 1 6 1 2 6 1

    Alex Smith 3 4 2 4 1 2 3 6

    Matt Ryan 2 1 2 4 * 1 3 4

    Matt Stafford 2 2 1 3 1 3 2 2

    T.J. Yates 2 2 2 1 2 1 2 4

    Andy Dalton 1 1 1 1 1 1 1 1

    1146 19th

    St., NW, Suite 200Washington, DC 20036(202) 463-7300

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    DEMOGRAPHICS

    Total Male Female WhiteAfrican

    AmericanHispanic 18-24 25-34 35-44 45-54 55+

    Tim Tebow 26 23 28 28 18 24 25 28 24 21 28

    Eli Manning 18 15 20 18 15 15 15 15 15 26 16

    Tom Brady 17 18 15 16 20 19 14 21 17 17 16

    Drew Brees 15 18 13 15 21 12 13 13 20 15 15

    Aaron Rodgers 7 8 6 9 3 3 9 5 7 5 9

    Ben Roethlisberger 4 5 4 5 6 2 5 5 5 4 4

    Joe Flacco 3 4 2 2 4 8 4 6 1 2 2

    Alex Smith 3 3 3 2 5 7 5 4 1 1 4

    Matt Ryan 2 2 3 2 1 3 4 1 2 5 1

    Matt Stafford 2 2 2 1 4 2 2 1 2 2 2

    T.J. Yates 2 2 2 1 3 6 2 1 6 1 1

    Andy Dalton 1 1 1 1 1 1 3 1 1 * 1

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    How to Calculate Bayesian Credibility Intervals

    The calculation of credibility intervals assumes that Y has a binomial distribution conditioned on the parameter \, i.e.,

    Y|~Bin(n,), where n is the size of our sample. In this setting, Y counts the

    . This model is often called the likelihood

    function, and it is a standard concept in both the Bayesian and the Classical framework. The Bayesian1

    statistics combines both

    the prior distribution and the likelihood function to create a posterior distribution. The posterior distribution represents ouropinion about which are the plausible values for adjusted after observing the sample data. In reality, the posterior

    distribution is ones knowledge base updated using the latest survey information. For the prior and likelihood functions

    specified here, the posterior distribution is also a beta distribution ((/y)~(y+a,n-y+b)), but with updated hyper-parameters.

    Our credibility interval for is based on this posterior distribution. As mentioned above, these intervals represent our belief

    about which are the most plausible values for given our updated knowledge base. There are different ways to calculate these

    intervals based on . Since we want only one measure of precision for all variables in the survey, analogous to what is

    done within the Classical framework, we will compute the largest possible credibility interval for any observed sample. The

    worst case occurs when we assume that a=1 and b=1 and . Using a simple approximation of the posterior by the

    normal distribution, the 95% credibility interval is given by, approximately:

    ..

    For the QB poll published on February 3rd

    , 2012, the Bayesian Credibility Interval was adjusted using standard weighting design

    effect 1+L=1.3 to account for complex weighting2

    Analysis Domain Sample size Credibility intervals

    American public (online sample) 2475 2.3%

    1Bayesian Data Analysis, Second Edition, Andrew Gelman, John B. Carlin, Hal S. Stern, Donald B. Rubin, Chapman & Hall/CRC |

    ISBN: 158488388X | 2003

    2Kish, L. (1992). Weighting for unequal Pi . Journal of Official, Statistics, 8, 2, 183200.