As a sort of summary on the main question, I think the political science view on pre-election polls is mildly negative (or at best mixed) in the sense that several studies observed that pre-election polls lower turnout in general, but there's also some evidence to the contrary that (published) polls can increase turnout when they announce a close election.
Also, pre-election polling also enables (better) strategic voting--and even not voting can count as such behavior in some circumstances. The question therefore devolves into a discussion whether strategic voting is good or bad--the kind of discussion that is more the realm of philosophers than political scientists.
Since you also criticized issue polling in your question, it is trivially more useful/scientific than the alternative of waiting for irate/loudest constituents to write to their representatives etc. Simply because of sampling rigor.
In some locations, including the EU, there's regular issue polling conducted by official institutions, e.g. Eurobaromter. US government grants that pay for similar things, e.g. the General Social Survey (GSS).
Now if you want some generic defense of polling, here's WAPORs:
Limiting the publication of opinion polls hurts everyone -- the public, the government, and even decision-makers -- because among other things, polls transmit citizens' goals, attitudes and desires, to governments and political parties. Polls give governments and parties better ability to represent and serve voters.
Somewhat "subtly" (not really), the don't quite make a distinction between issue polling and candidate/party polling in that statement...
As far as pre-election polls on candidate/party elections, what Philipp is probably trying to hint to is that they are banned in some countries within a certain time period of actual elections. According to a 2016 BBC article 38 countries have some kind of ban like that. The previously linked WAPOR paper flags four countries in which the ban is 30 days long before the election. And in ten more countries, the ban is for two weeks. In fact, a summary table summarizes this in more detail:
As for reasons why such bans exist, indeed it has been argued that they may demotivate voter turnout etc., so there may be some downsides to them. And there's some data to back this up:
using survey data and state-level election results from US presidential elections from 2000 to 2012 and find strong evidence that voters are influenced by polls—not in whom they vote for, but rather in whether they vote at all. [...]
Were polls wildly wrong—if they predicted a
lopsided victory for a candidate whose “true” support were less than the opposing candidate—
our data indicate that they could conceivably manufacture a victory for the “wrong” candidate, or
at least a more competitive election than either that predicted or what would have occurred in the
absence of polling.
(emphasis in original). Not measured in that paper, but conceivably:
in three-candidate races strategic voters might use predicted election results to vote strategically (cf., e.g., Cox 1997; McAllister and Studlar 1991).
Fivethrityeight actually has their own page on the topic, which highlights concurrence on that turnout issue with some French results/paper:
in 2013, researchers used a change in French law to get an idea of the potential impact of polls on voter turnout. Prior to 2005, citizens of France who lived in territories west of the country didn’t get to vote until after the mainland election had ended. Thus, they had the chance to see exit polls before they even went to cast their ballots. That changed after 2005, so researchers could compare several years worth of elections and see how knowledge of the presumed winner changed voter behavior. The result: After 2005, there was a nearly 12 percentage point increase in voter turnout. Far more people in those overseas territories voted when they didn’t already know who the winner was — a finding that has big implications for countries like the United States, where time zone differences mean voters in one part of the country can see the completed exit polls from earlier in the day.
Alas the rest of the page is somewhat less well written because it then "counters" that with the much more uncertain bandwagon effect (i.e. not just turnout, but whom those who do turn out vote for being influenced by polls). The US states paper didn't find such a bandwagon effect either, and a Dutch paper that 538 discusses also finds that even in hypothetical experiments a bandwagon effect from polls is hard to demonstrate, although possible with the "right narrative".
On the other hand, a Swiss study found a contrary effect, when polls predict a close race:
Closer elections are associated with greater turnout only when polls exist. Examining within-election variation in newspaper reporting on polls across cantons, we find that close polls increase turnout significantly more where newspapers report on them most.
Technically however, this study was on referenda and not regular elections.
Now a counter-argument to ban/blackouts is that polls may be hard to suppress nowadays:
Pollsters object that, in the event of a ban, privately commissioned polls would be commissioned and their findings published abroad and then reported in the [national] media. It would be virtually impossible to suppress them in this age of the internet.
ACE has some amusing examples of how some of this is/was done.
Since pre-election polling (better) enables strategic (aka tactical) voting (when there are 3 or more candidates), we now have to turn to that topic whether that is considered good or bad. Alas it gets pretty philosophical and not much researched in that regard (although there are tons of studies as to extent to which it happens), e.g.
it would be interesting to examine whether tactical voting can also have significant effects on citizens’ satisfaction with democracy. Although there is a vast empirical literature on the impact of electoral systems on overall satisfaction with democracy (Aarts and Thomassen 2008; Anderson and Guillory 1997; Dalton and Anderson 2011), there has been little systematic research on the microfoundations of this effect. Theoretically, tactical voters should be less satisfied than sincere voters, controlling for the winner/loser gap.
Actually, to make the matter a bit more complicated, even not voting
can be considered strategic behavior in some circumstances (see The Many Faces of Strategic Voting, p. 6). So it's not even clear that absenteeism (triggered by pre-election polls) is always a bad thing, if the voter does this strategically, with the intention of affecting the election outcome that way.
And to see why strategic voting is ultimately a phislophical issue (if want to judge whether it's good or bad), I'll have to resort to such a discussion from a newspaper, as political scientists seem to eschew the issue:
Some people react strongly against this sort of consequence-based reasoning. Their stance is that voting in a general election is an opportunity to express your political viewpoint. You do that by casting your vote in a sincere way. Tactical voting is insincere and cynical since you don’t really support the candidate you’re voting for. Immanuel Kant would presumably have railed against tactical voting as it goes against his formulation of the categorical imperative: treat others as ends in themselves, never as means to an end. Instead, you use that candidate to get the desired result of a majority in parliament for your preferred party.
The insincere vote is also tantamount to a lie, since you don’t really want the chosen candidate to represent you yet your cross against their name implies that you do. What you want is for the chosen candidate to defeat the Tory candidate, and that’s not the same thing. Kant was notoriously absolutist on the ethics of lying: it’s wrong in every conceivable situation, even when a crazed axeman shows up at your house asking where your best friend is.
Against this, it could be argued that the voting procedure doesn’t require you to vote for the candidate whose party you want to win, only to put an X against the name of your chosen candidate, so tactical voting doesn’t involve a lie. You are free to choose the candidate for whatever reason you like, including to block another candidate. If you take that view, there is nothing insincere at all about tactical voting.
A utilitarian might argue that using your vote in this way is sincere, sophisticated and moral. For those who see probable outcomes rather than intentions as determining the morality of actions, someone who votes tactically wishing the best outcome for the country is taking the course of action most likely to maximise happiness – provided, of course, the pollsters are reasonably accurate about how the candidates in a constituency are faring against each other.
Yet there is the niggling worry that there might be something wrong with tactical voting. Is this just naive idealism about what political participation should be? Not necessarily. For some, the emotional cost of voting for a candidate or party they don’t sincerely believe in may be high even when they can see the logical arguments for doing so.
Although rationally justifiable, this will feel like a betrayal even if good comes from it. We can know what is ultimately for the best and still feel terrible doing it. These negative psychological factors would have to be included in any utilitarian analysis, weighing the small benefit of a single tactical vote to the outcome against the personal cost of emotional turmoil.
So even on a utilitarian analysis, tactical voting may not be the best course of action. It all depends on what kind of a person you are – and how you will feel about casting a vote for someone you don’t want elected.
