The election of Donald Trump — and the prospect of his re-election — has been credited to everything from institutionalised racism in America to rising inequality.

But according to Richard Layard, founder and former director of the Centre for Economic Performance at the London School of Economics, the answer is simpler — it’s about happiness. If you look across the 3,096 US counties that participated in the 2016 election, votes for Trump were better explained by the average level of happiness in the county (self-reported, a measure that is apparently quite accurate) than by its unemployment, income or growth rate.

By this calculation, Democrats wishing to prevent Trump 2 would do best to focus on which candidate will make the most people happy, rather than the policy particulars of tax, healthcare or foreign policy. Of course, the latter can help facilitate the former, which is the one of the messages that Layard pushes in his interesting (albeit overly sweeping) look at the new science of happiness and how we can harness it to improve ourselves, our relationships and our societies.