The royal baby is great news for William and Kate, but is it also good news for British tourism?It's certainly a popular argument with fans of the British monarchy -- that the institution raises Britain's profile overseas and helps to boost tourist visits.The Daily Mail newspaper clearly hopes for such an effect from the recent arrival of the third in line to the British throne."Royal baby could cause tourism surge as well-wishers flock to UK," the paper trumpeted just after the birth of the new Prince of Cambridge."As London wakes up to the aftermath of a giant party on the Mall and the announcement that the Duke and Duchess of Cambridge have a son, there are hopes that the birth of the new royal baby will spark a tourism boom as well-wishers flock to the UK to people share in the joy," Britain's second best-selling paper went on in its picture-rich splash."The spell cast by the monarchy's 1,000-year history, combined with the international media frenzy around the royal baby, is extremely powerful at drawing to England," Lady Cobham, chair of the tourist body VisitBritain, is quoted as saying.Not alone The Daily Mail wasn't alone in predicting such an effect."Hotels and attractions" in London were set to capitalize on the "royal baby boom," observed the International Business Times.And that boom was apparently resonating beyond London."Royal Baby to spark rise in tourist visits," read an Edinburgh Evening News headline."Royal attractions in Edinburgh are expecting a surge in visitor numbers as tourists flock to share in the baby joy," the article said.Yet further afield (although still in a Commonwealth country) the travel editor of the Star, in Toronto, was not "necessarily gung ho" about the royal family but he still devoted a blog post to the "bounce" it was sure to give British tourism.On social media, "A British Royal baby could spark a major boost to the UK tourism industry," was a typical comment from Airwise News.Where's the evidence?Looking for evidence for the widely touted princeling-tourism connection, the evidence becomes less clear.Certainly tourists flocked to Buckingham Palace in advance of the birth, awaiting confirmation of the baby's arrival."Our holiday was booked months ago, so we did not expect to be over here while the baby was happening [but we've] been told to bring back as many newspapers and souvenirs with the baby on as possible," Matthew and Donna Harold, from Michigan, told the Telegraph.A scan of social media reveals the odd international prince-fixated quote, such as this from a tweeter in Fort Lauderdale, Florida: "Dear Kate Middleton, Please wait to have the Royal Baby until Thursday. Thank you, Annie Harley, an American Tourist."But are there any hard numbers to support the idea of a baby-born tourist surge?The Mail did cite a statistical precedent. In 2012, it said, the Queen's Diamond Jubilee year, tourist visits (at 31 million) were at their highest level since the beginning of the economic downturn in 2008.However, even if hotels near Kensington Palace are throwing caution to the wind with "Tot-ter Around Kensington" shop-and-stay packages and converting luxury suites into five-star nurseries for the occasion, that still doesn't turn correlation into cause.Negative effect?If anything, the numbers point the other way.A recent story in the Guardian refers to a document obtained under Freedom of Information legislation from Visit Britain on the marriage between Prince Andrew and Sarah Ferguson in 1986."We find that across the year as a whole there were 4% fewer visitors to Britain than in 1985, but that in July [1986] there were 8% fewer than in July of 1985," the document says."[S]uch as it is, the evidence points to royal weddings having a negative impact on inbound tourism."Graham Smith, chief executive officer of the campaign group Republic, concurs.The argument that royal births, weddings and anniversaries benefit tourism is "a complete fiction," he tells CNN."There's not a shred of evidence for it. People don't make holiday decisions on the basis of who's living in what castle."Tourists are here for our culture, our common language. They may come and look at palaces but the fairy tale side of it is there regardless of whether the monarchy is or not."People have nothing [substantive] to say in defense of the monarchy so come up with a financial argument."Culture and heritage"We know that visitors drawn to Britain by the appeal of our culture and heritage spend over £4.5 billion annually and support around 100,000 jobs," a VisitBritain official tells CNN."This in part can be attributed to attractions and events with a connection to Britain's monarchs past and present."Kate and William's wedding in 2011, VisitBritain says, "brought record numbers of visitors for the summer opening of Buckingham Palace.More than 600,000 people passed through the gates to see the Duchess of Cambridge's wedding dress."That smashed the previous attendance figure set in 1994 and was an increase of almost 50%" on the previous year, says VisitBritain.Such figures are compelling.But whether anybody actually booked tickets to Britain for the birth of George Alexander Louis or any other royal event, as so many people in Britain and beyond seem to think, is far less certain.