Want to come up with a winning election ad campaign? Just be honest

Joe Biden announced he was running for re-election in a video released in April 2023. Photograph: Biden Harris Presidential Campai/AFP/Getty Images

There are so many elections this year but how to go about winning them? Labour has a sub-optimal, but impressively consistent strategy: waiting (usually a decade and a half in opposition).

It’s paying off again with huge swings to them in last week’s two byelections. But this approach requires patience and most parties around the world are less keen on waiting that long. So they spend a lot of time and money trying to win, which means election adverts. In the US, TV ads are centre stage. In the UK, those are largely banned (even GB News is meant to be providing news when Tory MPs interview each other) but online ads are big business.

The kind of ads that worked in 2018 didn’t have the same effect in 2020

Those involved in politics have very strong views about the kind of ads that work. They absolutely have to be positive about your offer. Or negative about your ghastly opponent. It’s imperative they’re about issues, not personalities. Or the opposite. The only problem with those election gurus’ certainties? Different kinds of ads work at different times and places. So found research with access to an intriguing data source: experiments conducted by campaign teams during 2018 and 2020 US elections to test ad options before choosing which to air; 617 ads were tested in 146 survey experiments.

Researchers showed that quality matters – it’s not unusual for an advert to be 50% more or less persuasive than average. But one kind is not generally more persuasive and the type of ads that worked in 2018 didn’t have the same effect in 2020.

So, if you’re trying to get yourself elected, my advice is to base your campaign on the evidence, not just your hunch. See it as good practice. After all, we’d ideally run the country that way.

• Torsten Bell is chief executive of the Resolution Foundation and author of the forthcoming book Great Britain? How We Get Our Future Back