The complexity of opinion polls were the subject of a conference organised by the Luxembourg Society of Statistics (SLS).

Opinion polls sometimes influence the policies pursued by politicians, but at their core they are supposed to reflect public opinion. The SLS wanted to discuss the complexities of opinion polls in relation to statistics and political science, and organised a conference on the subject on Tuesday.

The conclusion is, in short, that opinion polls need to be taken with a pinch of salt. Trump and Brexit have shown that the results of opinion polls can differ widely from final election results. This can have several reasons. For instance, perceived social pressures may lead people to give what they believe to be the more popular or widely accepted answer when polled, or they may simply change their minds on election day.

Another factor is found in the various methodologies that are used to gather people’s opinions, to adjust them and to assess them. IN Luxembourg as elsewhere, these have often been subject to criticism. Tommy Klein from TNS Ilres points to the fact that there are ways to improve the survey methodology, but this would also cost more. However, he insists that Ilres does not engage in cheap and unreliable opinion polling, and says that "Ilres has a certain responsibility to sell and produce numbers that are reliable."

‘Opinion polls tell people what they think,’ said the French comedian Coluche. This stance is not far removed from the analyses made by many specialists. University professor Raphael Kies explains that there is an effect leading politicians to pay too much attention to opinion polls and act in accordance with what they think will get them good results in the polls. As a consequence, the long-term view is often neglected.

A new kind of opinions polls could be social networks. After analysing the campaigns ahead of the referendum in 2015, Raphael Kies noted that the opinions expressed on the RTL and L'essentiel forums were comparable to the actual result.

It’s a fact that more and more people, who until now had no voice in traditional media, express their opinion online. "Discussion forums and social media are comparable to one another," says Raphaël Kies, adding that people who express their opinion on these networks have quite a high level of education and tend to be critical of their society. They could correspond to the new generation of ‘opinion leaders’. During the conference, it was also noted that the reform of the law on political opinion polls of 2015 is not clear enough.