If Olympic euphoria has indeed urged procreation, the boom would have been seen in 2013, when the birth rate actually dipped.

In December, in a pre-election interview with The Sunday Times, UK Prime Minister Boris Johnson had predicted that after Brexit, Britons would fall into each other’s arms in euphoric relief and celebrate the end of uncertainty by breeding like bunny-rabbits. He promised that for sheer scale, it would rival another baby boom that he had allegedly set off with the London Olympics in 2012, when he was mayor of the capital. As always, Boris was hazy on the details. If Olympic euphoria has indeed urged procreation, the boom would have been seen in 2013, when the birth rate actually dipped.

But this time, he has baffled scoffers by leading by example from No 10, as credibly as Churchill ever did in Britain’s darkest hour. Johnson has announced that his partner Carrie Symonds is expecting, and that they are engaged. Can this development be directly attributed to post-election euphoria in Downing Street? Johnson is right in assuming that relief encourages people to have children. The original baby boom of the mid-20th century owed to euphoria at the end of World War II and massive efforts towards recovery and rehabilitation in most of the nations involved. But in post-Brexit Britain, just thinking of the European wines and cheeses that will dwindle on menus must be depressing, and never mind the economic woes ahead.

Besides, popular thinking about baby booms is not always reliable. It is widely believed that a boom followed a blackout in the US north-east in 1965, because people had nothing better to do. In reality, the 13-hour outage only irritated people, and procreation was the last thing on their minds. As for Johnson’s post-Olympic boom, The Sunday Times attributed it to the publication of Fifty Shades of Grey, rather than to any efforts by Boris Johnson to increase public happiness.