The Minimal Effects of TV Debates Between Candidates

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Yves here. While we hope you all will join us for Lambert’s usual debate open thread tomorrow night, if nothing else as a way to keep on top of what will be the news event of the week without losing your sanity, this post serves as an important reminder that the stakes aren’t as high as the media would have you believe. In the US, the data suggests that unlike the mother of all televised debates, Kennedy v. Nixon in 1960, debates don’t do much to change voter views in the US. That may be due to the candidates having been well exposed to the electorate before the debates, so they already have a good sense of the contenders’ personalities and positions.

Another way to think about it is whatever shifting of voter views occurs during the debates could be offset or solidified by later developments. For instance, Obama, who was not doing well given his incumbent status in 2012, was widely perceived to have also dialed in his performance at the first debate with Romney, giving the challenger a further boost. But Obama prepped for the next three debates and was generally credited with having won them.

However, consistent with the thesis of this post, those debates likely had less impact than the release of a secret video taken at a Romney fundraiser. His remarks:

There are 47 percent of the people who will vote for the president no matter what. All right, there are 47 percent who are with him, who are dependent upon government, who believe that they are victims, who believe the government has a responsibility to care for them, who believe that they are entitled to health care, to food, to housing, to you-name-it. That that’s an entitlement. And the government should give it to them. And they will vote for this president no matter what…These are people who pay no income tax.

Funny how this is a mirror image of Hillary Clinton’s self-destructive “basket of deplorables” declaration.

By Caroline Le Pennec, Incoming Assistant Professor, HEC Montréal; Vincent Pons, Assistant Professor of Business Administration, Harvard Business School, and Faculty Research Fellow at NBER; Vestal McIntyre, writer and editor on development economics for the Economic Growth Center at Yale University, and other organizations. Originally published at VoxEU

The first televised debate between US President Donald Trump and Democratic challenger Joe Biden will take place next week. But while it is being portrayed as a make-or-break moment in the campaign, this column argues that TV debates between candidates do not substantially impact vote choice. Instead, a campaign wishing to sway last-minute voters might do better by focusing on individual outreach – a challenging prospect, given the Covid-19 pandemic.

The first televised debate between US President Donald Trump and Democratic challenger Joe Biden will take place on 29 September. The US media often portrays this as a make-or-break moment in the campaign. One CNN analysis claims that “[t]he best opportunity [Trump] will have to alter the race’s trajectory is the three debates with Biden, especially the first one, on September 29, since traditionally that is the one that draws the most viewers,” and Vanity Fair magazine says that “[t]he presidential debates of 2020 will likely be this country’s most dramatic and consequential political theater of the 21st century.”

But how many voters will change their choice based on what they see?

A large number of US-based studies examine this question. While some conclude that TV debates truly matter (e.g. Hillygus and Jackman 2003), others find modest or even null effects on vote choice (e.g. Shaw 1999). However, these studies generally focus on a unique election or a small number of races in the same country, and so their estimates may capture the effects of concomitant events and underlying time trends.

Another set of studies use rigorous experimentation in developing countries and find that debates can build voter knowledge and affect voter choice (Brierley et al. 2019, Bidwell et al. 2019, Platas and Raffler 2019, Bowles and Larreguy 2020). Brierley et al. (2019) show debates also reduce polarisation in Ghana, while for Sierra Leone Bidwell et al. (2019) trace the effects all the way through to the behaviour of elected members of parliament, and give evidence that debates increase accountability and lead to policy change.

However, these studies are quite far removed from the US electoral season, focusing instead on debates in low-income democracies with scarce information. The debates feature parliamentary candidates (not executives) and they are not televised but featured on smartphones, in public gatherings, or on the radio.

In a new paper, two of us – Caroline and Vincent – use survey data from 62 elections in ten OECD countries to begin to fill this knowledge gap (Le Pennec and Pons 2020). Voters are surveyed not once, but twice – before and after election day – which provides new detail on how and when they make their choices.

We find that across the sample of countries, a significant portion of survey respondents can still be swayed in the last 60 days in a campaign – enough to change the outcomes of many elections. However, this share is far lower in the US, and across all countries and elections considered, TV debates do not substantially impact vote choice.

This suggests a campaign wishing to sway last-minute voters might do better by focusing on individual outreach – a challenging prospect, given the Covid-19 pandemic.

The Surveys

In the paper, we seek to identify the overall impact of information voters receive across an electoral season, and how that compares to other factors such as party affiliation in determining their vote. We assemble a dataset of nationally representative surveys conducted around 62 elections in ten countries from 1952 to 2017, resulting in a total of 253,000 observations.

These surveys entailed interviewing a new set of people every day before the election to elicit their voting intentions, then interviewing them again after the election to record their actual vote choice. Comparing voters’ responses to the two surveys reveals whether they had actually settled on their final vote choice by the time of the pre-electoral survey, removing recollection bias which can arise when asking voters when they made their choice and what made them choose.

The paper sheds light on a number of determinates of voter choice, such as policy preferences (information received during the electoral season does not appear to affect policy preferences expressed before and after an election), candidate electability (surveys suggest that voters’ beliefs on candidates’ attributes and policy positions matter more than beliefs on their chances of victory), and the perceived importance of different issues (which changes during the campaign and correlates with shifts in vote choices).

But three of the findings speak directly to the possible effects of the 29 September debate:

1. Across the sample, sufficient numbers of voters make their choice in the final two months to sway many elections

As Figure 1 shows, the surveys reveal that the fraction of people with identical pre-election vote intention and post-election vote declaration increases by 17 percentage points over the last 60 days before the election, from a baseline of 71%. That increase comes both from respondents becoming more willing to state any vote intention, and from that statement becoming more consistent with their final reported vote.

Figure 1 Vote choice consistency as a function of the number of days relative to the election

2. Far fewer voters are subject to last-minute changes in the US than other countries

The influence of campaigns on vote choice has been relatively stable for the last 70 years but it varies substantially from one country to another.

Figure 2 represents this, by showing vote choice consistency across countries and over time. For each election, we estimate the average daily increase in the fraction of people with identical vote intention and vote declaration in the last 60 days before the election. The figure plots these election-specific estimates – the daily increases in vote choice consistency – against election year, along with country-level linear fits. The share of voters who change their mind in the final two months of an election season is much lower in the US than in other countries and this has changed little over the decades.

Figure 2 Average daily increase in vote choice consistency across countries and over time

3. TV debates change few minds

The study sheds light on the effects of 56 TV debates in 31 elections in seven countries, which not only gives the results the advantage of statistical power, but also a broader focus than studies such as Hillygus and Jackman (2003) and Shaw (1999), which focus on a few elections in a single country.

The methodology confers two further advantages in identifying the effects of debates. First, the fact that there are many debates in the samples decreases the risk that the event study captures the effect of other shocks affecting vote choice – as we can reasonably assume such shocks should be uncorrelated with the dates of debates. And second, debates took place at different times in different elections, which allows an ability to control flexibly for the consistency of vote choice that rises non-linearly in the 60 days leading to the election, as we saw in Figure 1. In other words, effects of debates can be disentangled from those underlying time trends.

The results show no significant impact of TV debates on individual consistency between vote intentions and vote choices expressed before and after an election – or any of the other relevant factors considered, such as voter policy preferences, issue salience, or beliefs on candidates. Thanks to the precision of the estimates, we can reject any impact higher than 0.5 percentage points on vote choice consistency, on average. Furthermore, debates do not contribute to vote choice formation for any type of voters and in any context, including close and uncertain races.

If Not Debates, What Will Sway Last-Minute Voters?

Unlike televised debates, door-to-door canvassing by political activists has a strong potential to mobilise and persuade voters – at least in France, according to a series of studies one of us (Vincent) conducted with co-authors. It can bring in new voters through registration (Braconnier et al. 2017) and mobilise a party’s existing supporters to vote (Pons and Liegey 2019).

Vincent also gave evidence that canvassing can perform that function so often attributed to TV debates – changing minds. He embedded a countrywide experiment in François Hollande’s campaign in the 2012 French presidential election (Pons 2018), randomising who received visits as an estimated 80,000 left-wing activists knocked on 5 million doors to encourage people to vote for Hollande. The study found that canvassers did not affect turnout, but increased Hollande’s vote share by 3.2 percentage points in the first round and 2.8 points in the second, accounting for a quarter of his victory margin.

What bearing will these findings have on an election in the United States, and especially one taking place during a global pandemic? Republicans and Democrats are taking a dramatically different approach to field work. Donald Trump’s campaign recently claimed to have knocked on 1 million doors in one week, while Joe Biden’s campaign knocked on zero, choosing instead to focus on safer methods such as phone calls, texts, and virtual organising.

It is hard to say if such efforts will change many voters’ minds, but if past evidence holds true, the TV debates will not.

See original post for references

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  1. vlade

    The only thing I suspect could make a change in debate today is if Biden collapses for health reasons.

    I’m discounting incoherency, as likely both are going to be incoherent.

  2. AnonyMouse

    How infuriating it is to see the neolib press going endlessly on about how “the bar for Biden has been lowered so that anything short of senility will be seen as a success.”

    I still remember when I was arguing in the primaries that dementia would be the main line of attack against Biden… and I was reassured that “Trump wouldn’t do that” because it “wouldn’t play well!”

    The reality is everyone will be watching and hoping he doesn’t get flustered, ready to spin if he does.

    Is it truly beyond the ken of man for even the establishment to prop up a candidate without such an obvious achilles heel?

  3. Noone from Nowheresville

    Where’s the bias of the moderators? How about the constant re-hashing of the pundits during and after the debate telling the audience what to think about what they just saw even if it’s not what they just saw or even heard?

    Each PR channel does their own bit to play up the greatest hits and ignore the pieces which don’t work for their narrative. But that’s far beyond just elections.

    Anyone remember that first Mondale Reagan debate? Remember how Reagan “won” that first debate? TV is all about shaping the narrative.

    I’m hoping for a very good staged show with a few actual real moments. Do I expect much in the way of changed minds? Nope. Not unless one of the combatants suffers a major meltdown or lands some type of knockout blow. Less likely with the final two social club combatants. What I do expect to learn are hints about the potential plot threads for the 2021 show.

    I wonder if I need something meatier than popcorn. I am hoping for some fireworks and momentary soon to be forgotten truth moments. Trump does like to sprinkle few truth cherries amid the peanuts. Both sides will want to whip up that cream to a nice foamy light consistency without churning it into butter. I wonder which flavor will be included with the vanilla and chocolate scoops. And lots and lots of bananas so the boat really floats.

    1. lyman alpha blob

      Remember how Reagan “won” that first debate?

      And didn’t they repeatedly tout W in the 2000 campaign as never having lost a debate? And he was a complete moron, although arguably a slightly more articulate one than Trump.

      1. Noone from Nowheresville

        Yep, isn’t it amazing what propaganda can do. Turn white into black. Up into down. vice versa. Vicious to the point where it becomes dangerous for the ordinary person to even “think” about what’s truth.

        I have to disagree. I think Trump has mad skills and comedic timing when you watch his live shows. He’s a born audience hog performer. Natural ability which someone(s) helped him hone. Is he somewhat of a joke on a certain level? Sure but there’s a method to his seeming madness as well as very specific use of language which speaks directly to his audience and their communities. That makes him dangerous on multiple levels. Biden doesn’t have those skills or that same type of community reinforcement / disclipline.

        Is Trump book smart brilliant? Nah. He doesn’t have to be. He’s clever and ruthless and knows one hires other ruthless people to find the loopholes, manipulate the hazy grays of any rules then pay the eventual slap on the wrist. Perhaps slightly less lazy than W but only because he likes to bath in the spotlight of his own image. Whereas W seemed like he could take it or leave it.

        Who knows what will happen once W’s fully rehabilitated. By 2024 he could become the wise elder statesman compared to Trump’s gambler showboating routine. A “sane” choice in this propaganda bizarro world.

  4. The Historian

    Well, if you watch the debates, I guess you could count the number of times Trump says “I am the greatest” or count the number of times Biden trips over his tongue, but other than that, what value is there? Are they going to discuss policy? Are we going to see clear differences between what they will do about Covid or medical care or worker security or any other of the real issues this country faces? No matter what happens, each side will start with the spin immediately after.

    I guess if people want to watch two grown men throw meaningless verbal jabs at each other, since we no longer have Hope and Crosby, the debates might have some value as entertainment.

    1. The Rev Kev

      It will be like watching a debate between Biff Tannen and Grampa Simpson. A new drinking game for then – every time a candidate makes a clear, logical, articulate argument, you have to take a swig out of a bottle. Don’t get your hopes up though.

      Said it before and will say it again. People like Trump are not the problem. They are the symptom of a problem. And that problem is a corrupt political system that gives you such people as candidates. In lieu of them – Laurel and Hardy reruns are good but Abbott & Costello would be even better.

          1. vlade

            Nah, I lived in NZ. Oz only for visits (hols and work). But Oz politics was always way more fun than NZ ones. NZ papers front page was booring, and from the rest only sports page worth reading unless one wanted to fall asleep (or was interested in farming prices).

  5. ObjectiveFunction

    Trump doesn’t *do* prep, or talking points. Nor does he answer questions that don’t suit him. He wings it, blurting out whatever enters his head, just as he did in the debates with Hillary, and has in all his rallies before and since. And that seems to describe his Cabinet meetings too, or so I hear.

    So I expect Trump to upend the debate chessboard entirely, knowing all the knives are out for him. He’ll deflect the ‘Mr President, when will you stop denying your hands are stained with the blood of 200,000 Americans?” questions to denounce the bias and fake news of the Failing Media, who he and his base really does hate (with some reason). I expect him to largely ignore Biden too, at first.

    If the mods get drawn into arguing with Trump or trying to bring him into line, Joe will risk looking marginal and befuddled. Or else, being used to being alpha dog himself, and perhaps with that Giant Shot in the Ass(c) (lol!) to fortify him, he’ll get lured off his script and try to join in the mud wrestling. And that’s when the fun really starts!

    My best guess. Must see TV.


  6. Winston Smith

    I barely managed to watch 20 minutes of this stomach churning affair in 2016 and tuesday evening will dutifully avoid exposure to what could lead to instantaneous barf-O-rama.

    It will be a sorry spectacle and a further indication that the US is in a free fall

  7. gnatt

    gore went into the first debate with bush leading in the polls more than biden is leading trump now. watch the first few minutes. bush, never brave without chaney up his spine, looks scared. gore starts droning on about preserving social security by putting it in a “lockbox,” and on and on. bush’s face brightens as he realizes that gore is defeating himself.
    every time i’ve seen biden the past few months he seems like a ghost. trump’s energy is crazy and ferocious. i’m not convinced that this won’t affect enough people to change the polls.

  8. sharonsj

    I stopped watching debates a long time ago when I realized what politicians say means nothing. It’s what they do. So all I need to know about both Trump and Biden have already been revealed. I’m voting for neither because we are screwed either way. But I like the idea of still getting drunk.

  9. Alex Cox

    I’m hoping that whoever asks the questions will enquire: “What happens to all the Americans who are scheduled to lose their homes immediately after the election? What will you do for them?”

    Wonder if anyone will ask that.

  10. Wukchumni

    Tonight’s AA drinking word is ‘Betty Ford’, which seems safe on the surface, but does the teetotalitarian go to it, possibly driving those on the wagon back to the bottle?

  11. Darthbobber

    Some debates matter, some don’t. I think the Bush-Gore ones mattered, not because of any points made, but because of the overhandled Gore showing up with 3 seemingly distinct personalities for the three debates.

    I suspect the Biden-Palin VP debate also had an impact, as Palin managed to underperform even the low bar set for her. I also remember the audience-commentator division being on display for that one, as the commentators man and womanfully strove to portray the honors as nearly even until it became clear that the viewers couldn’t be persuaded to see it quite that way.

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