![\"Measures](\"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/2016\/01\/PM_2016-01-07_likely-voters_AppA-01.png\")
<\/a><\/figure>\n\nThe most direct way of predicting voter turnout is to simply ask whether a person intends to vote or not. And, in fact, this is the likely voter method that many pollsters use: Those respondents who say they will vote are included in the survey; those who say they won\u2019t vote are not. There are a variety of different ways of asking the \u201cdo you plan to vote\u201d item. Since the vast majority of registered voters (90% or more) say they plan to vote, many researchers ask a follow-up question to gauge certainty of voting among those who plan to vote.<\/p>\n\n
In the American Trends Panel, we asked a slightly different question about the respondent\u2019s likelihood of voting: 70% of registered voters told us they \u201cdefinitely\u201d would be voting in the 2014 election. More than three-quarters (77%) of this group were verified as having voted, compared with only 36% among those who said they were \u201cprobably\u201d going to vote. The \u201cprobably will vote\u201d group also has a skewed partisan makeup (36% Republican, 54% Democrat) compared with those who said they would definitely be voting (46% Republican, 48% Democrat).<\/p>\n\n
A different way to get at a similar concept is by asking respondents to rate their likelihood to vote on a 1 to 10 scale. Fully 75% of respondents rate the likelihood as a 9 or 10, giving them a point on the scale. A 75% majority of those voters are verified as having voted. By comparison, only one-third (34%) of those rating a 7 or 8 were verified as having voted.<\/p>\n\n
Both of these measures do a good job of identifying nonvoters. Most of those who say they won\u2019t vote, or that there is a low likelihood that they will vote, in fact do not turn out. But the challenge in surveys is that relatively few registered voters say they won\u2019t vote.<\/p>\n\n
Measures of voter engagement<\/h3>\n\n![\"Measures](\"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/2016\/01\/PM_2016-01-07_likely-voters_AppA-02.png\")
<\/a><\/figure>\n\nCitizens who are more interested in politics and who have been paying attention to the campaign are presumably more likely to vote than those who a\nre less interested. To measure engagement in the election, respondents were asked how much they had thought about the upcoming election. Fully 69% of respondents said they thought \u201cquite a lot\u201d or \u201cso\nme\u201d about the upcoming election. To measure general interest in politics, respondents were asked how often they follow government and public affairs; 77% of respondents said they follow government affairs \u201cmost of the time\u201d or \u201csome of the time.\u201d<\/p>\n\n
These questions are weaker at discriminating between voters and nonvoters than are the measures of vote intention. The Perry-Gallup scale assigns a point to respondents who say they have thought \u201cquite a lot\u201d or \u201csome\u201d about the election, but 55% of those who said they had thought \u201conly a little\u201d about the election also voted \u2013 and this group was one-fifth of the sample (21%). In addition, a substantial 43% turned out among those who said they follow government and public affairs \u201conly now and then.\u201d<\/p>\n\n
Measures of past voting behavior<\/h3>\n\n![\"Self-reported](\"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/2016\/01\/PM_2016-01-07_likely-voters_AppA-03.png\")
<\/a><\/figure>\n\nMeasures of past voting behavior are central to any gauge of the likelihood of voting. The Perry-Gallup index uses three measures of past voting: whether an individual voted in the previous presidential election, the individual\u2019s own assessment of how regularly he or she votes, and whether he or she has ever voted in their local precinct or election district. (Since respondents ages 18-21 may not have had the opportunity to vote in previous national elections, they typically are given an additional 1-point boost on the scale to compensate.)<\/p>\n\n
Past vote has been shown to be a strong predictor of future behavior. According to the voter file, respondents who said they voted in the 2012 presidential election were more than four times as likely as those who did not vote to have voted in 2014. While some voters who say they did not vote in 2012 still turned out in 2014 (17% were verified as voters), an analysis of respondents matched to the voter file shows that only 5% have a record of voting in 2014 but not 2012.<\/p>\n\n
Not surprisingly, self-reported regularity of voting also discriminates between voters and nonvoters. Fully 78% of respondents say\nthey always or nearly always vote in elections, and 82% of those who say they \u201calways\u201d vote were verified as 2014 voters, as were 59% among those who said they \u201cnearly always\u201d vote. That number drops significantly for those who say they vote \u201cpart of the time\u201d and those who say they \u201cseldom\u201d vote \u2013 only 34% and 17%, respectively, had a verified voting record for 2014.<\/p>\n\n![\"Voter](\"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/2016\/01\/PM_2016-01-07_likely-voters_AppA-04.png\")
<\/a><\/figure>\n\nMeasure of past voting also implicitly captures knowledge of how and where to vote. One standard question in the likely voter index asks about previous voting in the respondent\u2019s precinct or election district, and another asks about knowledge of where to vote. (This question may become increasingly irrelevant in an era of early voting and \u201cjust in time\u201d information on smartphones.) In midterm elections, only a question about past voting in one\u2019s precinct is typically included. Fully 83% of respondents say they had voted in their precinct in the past, and 70% of these are verified as 2014 voters. Among those who said they hadn\u2019t voted in their local election venue, just 26% were verified voters in 2014.<\/p>\n\n
Voter file records<\/h3>\n\n
Pollsters who draw their election samples from databases of registered voters \u2013 or those who are able to match their RDD respondents with the national voter file \u2013 have an additional source of information about past voting behavior: a verified record of voting in past elections. Voting history can also be used in a likely voter prediction model in the same way as the respondents\u2019 self-reports of past voting.<\/p>\n\n
As described earlier, 89% of the self-reported registered voters in the panel who completed both the pre-election and post-election waves were matched to a voter file that contains records of past voting dating back several election cycles.<\/p>\n\n
<\/a><\/figure>\n\nCitizens who are more interested in politics and who have been paying attention to the campaign are presumably more likely to vote than those who a\nre less interested. To measure engagement in the election, respondents were asked how much they had thought about the upcoming election. Fully 69% of respondents said they thought \u201cquite a lot\u201d or \u201cso\nme\u201d about the upcoming election. To measure general interest in politics, respondents were asked how often they follow government and public affairs; 77% of respondents said they follow government affairs \u201cmost of the time\u201d or \u201csome of the time.\u201d<\/p>\n\n
These questions are weaker at discriminating between voters and nonvoters than are the measures of vote intention. The Perry-Gallup scale assigns a point to respondents who say they have thought \u201cquite a lot\u201d or \u201csome\u201d about the election, but 55% of those who said they had thought \u201conly a little\u201d about the election also voted \u2013 and this group was one-fifth of the sample (21%). In addition, a substantial 43% turned out among those who said they follow government and public affairs \u201conly now and then.\u201d<\/p>\n\n
Measures of past voting behavior<\/h3>\n\n<\/a><\/figure>\n\nMeasures of past voting behavior are central to any gauge of the likelihood of voting. The Perry-Gallup index uses three measures of past voting: whether an individual voted in the previous presidential election, the individual\u2019s own assessment of how regularly he or she votes, and whether he or she has ever voted in their local precinct or election district. (Since respondents ages 18-21 may not have had the opportunity to vote in previous national elections, they typically are given an additional 1-point boost on the scale to compensate.)<\/p>\n\n
Past vote has been shown to be a strong predictor of future behavior. According to the voter file, respondents who said they voted in the 2012 presidential election were more than four times as likely as those who did not vote to have voted in 2014. While some voters who say they did not vote in 2012 still turned out in 2014 (17% were verified as voters), an analysis of respondents matched to the voter file shows that only 5% have a record of voting in 2014 but not 2012.<\/p>\n\n
Not surprisingly, self-reported regularity of voting also discriminates between voters and nonvoters. Fully 78% of respondents say\nthey always or nearly always vote in elections, and 82% of those who say they \u201calways\u201d vote were verified as 2014 voters, as were 59% among those who said they \u201cnearly always\u201d vote. That number drops significantly for those who say they vote \u201cpart of the time\u201d and those who say they \u201cseldom\u201d vote \u2013 only 34% and 17%, respectively, had a verified voting record for 2014.<\/p>\n\n<\/a><\/figure>\n\nMeasure of past voting also implicitly captures knowledge of how and where to vote. One standard question in the likely voter index asks about previous voting in the respondent\u2019s precinct or election district, and another asks about knowledge of where to vote. (This question may become increasingly irrelevant in an era of early voting and \u201cjust in time\u201d information on smartphones.) In midterm elections, only a question about past voting in one\u2019s precinct is typically included. Fully 83% of respondents say they had voted in their precinct in the past, and 70% of these are verified as 2014 voters. Among those who said they hadn\u2019t voted in their local election venue, just 26% were verified voters in 2014.<\/p>\n\n
Voter file records<\/h3>\n\n
Pollsters who draw their election samples from databases of registered voters \u2013 or those who are able to match their RDD respondents with the national voter file \u2013 have an additional source of information about past voting behavior: a verified record of voting in past elections. Voting history can also be used in a likely voter prediction model in the same way as the respondents\u2019 self-reports of past voting.<\/p>\n\n
As described earlier, 89% of the self-reported registered voters in the panel who completed both the pre-election and post-election waves were matched to a voter file that contains records of past voting dating back several election cycles.<\/p>\n\n
<\/a><\/figure>\n\nMeasures of past voting behavior are central to any gauge of the likelihood of voting. The Perry-Gallup index uses three measures of past voting: whether an individual voted in the previous presidential election, the individual\u2019s own assessment of how regularly he or she votes, and whether he or she has ever voted in their local precinct or election district. (Since respondents ages 18-21 may not have had the opportunity to vote in previous national elections, they typically are given an additional 1-point boost on the scale to compensate.)<\/p>\n\n
Past vote has been shown to be a strong predictor of future behavior. According to the voter file, respondents who said they voted in the 2012 presidential election were more than four times as likely as those who did not vote to have voted in 2014. While some voters who say they did not vote in 2012 still turned out in 2014 (17% were verified as voters), an analysis of respondents matched to the voter file shows that only 5% have a record of voting in 2014 but not 2012.<\/p>\n\n
Not surprisingly, self-reported regularity of voting also discriminates between voters and nonvoters. Fully 78% of respondents say\nthey always or nearly always vote in elections, and 82% of those who say they \u201calways\u201d vote were verified as 2014 voters, as were 59% among those who said they \u201cnearly always\u201d vote. That number drops significantly for those who say they vote \u201cpart of the time\u201d and those who say they \u201cseldom\u201d vote \u2013 only 34% and 17%, respectively, had a verified voting record for 2014.<\/p>\n\n Measure of past voting also implicitly captures knowledge of how and where to vote. One standard question in the likely voter index asks about previous voting in the respondent\u2019s precinct or election district, and another asks about knowledge of where to vote. (This question may become increasingly irrelevant in an era of early voting and \u201cjust in time\u201d information on smartphones.) In midterm elections, only a question about past voting in one\u2019s precinct is typically included. Fully 83% of respondents say they had voted in their precinct in the past, and 70% of these are verified as 2014 voters. Among those who said they hadn\u2019t voted in their local election venue, just 26% were verified voters in 2014.<\/p>\n\n Pollsters who draw their election samples from databases of registered voters \u2013 or those who are able to match their RDD respondents with the national voter file \u2013 have an additional source of information about past voting behavior: a verified record of voting in past elections. Voting history can also be used in a likely voter prediction model in the same way as the respondents\u2019 self-reports of past voting.<\/p>\n\n As described earlier, 89% of the self-reported registered voters in the panel who completed both the pre-election and post-election waves were matched to a voter file that contains records of past voting dating back several election cycles.<\/p>\n\n<\/a><\/figure>\n\nVoter file records<\/h3>\n\n