A few years ago I had a hunch about search rankings. It was well known that people click more on higher-ranked search results – partly out of laziness and partly because they trust them. Could that trust, I wondered, cause people’s opinions to change on issues on which they were undecided? Could it, perhaps, even change how people vote?
Randomized, controlled experiments Ronald Robertson and I began conducting in early 2013 demonstrated that search rankings do indeed have such powers. When one candidate is consistently favoured in search results – in other words, when high-ranking results link to web pages that make that candidate look better than his or her opponent – this can, in a large country, push millions of votes to the higher-ranked candidate, shifting up to 80 per cent of undecided voters in some demographic groups. Because this is such a large effect and because many elections are won by small margins, we believe that search rankings have been determining the outcomes of upwards of 25 per cent of the world’s national elections for years now, with increasing impact each year as internet penetration has increased.
