Princess Charlotte
Kate and her two children are worth nearly £10bn to the UK's economyAFP / Getty Images

Royal baby Princess Charlotte, Kate Middleton's daughter, is set to bring a huge uplift to the British economy, eclipsing the worth of Prince George, worth around £2.3bn. The so-called "Charlotte effect" has brought big dividends for brands associated with the princess. Her birth generated economic benefits of more than £100m, according to Brand Finance.

However, the royal family's top money earner is the Duchess of Cornwall, thought to be worth £4.7bn. "The unofficial endorsement of Charlotte, George and their mother Kate, in particular, has a profound financial effect running into millions annually," chief executive David Haigh of Brand Finance said.

One example of this effect are the children's clothing. When Prince William and Kate Middleton first introduced Princess Charlotte to the world's media in a lacy shawl, the product has sold strongly, according to the makers.

"We have seen a big increase in orders from all around the world, thanks to all the media coverage," Gillian Taylor, director of GH Hurt & Sons told the Sunday Express.

China loves royal warrants

Queen Elizabeth, the current sovereign, will become the longest-serving monarch in British history on 9 September. "As Queen Elizabeth approaches this historic milestone, she heads a Royal Family near a peak of popularity. Yet the old debate over whether the Monarchy should be retained continues to rage. The principle of whether monarchy is an appropriate and fair form of government in the 21st century certainly remains open to question. However Brand Finance's research shows that from an economic standpoint at least, the royalists firmly have the upper hand," said Haigh.

"A Royal Warrant can confer a significant premium to brands in certain industries such as luxury, food, sporting goods and fashion, yet are currently awarded at no cost to the holder. The introduction of royalties could provide a significant new revenue stream. The unofficial endorsement of Charlotte, George and Kate, in particular, has a profound financial effect running into millions annually. The demand for authentic connection to or emulation of key members of the royal family is by no means fulfilled. This too presents a major opportunity.

"Though the 'monetization' of the Monarchy may sound beyond the pale to some, in straightened times of continuing austerity in Britain, the Royal Family may come under increasing pressure to pay its way in more ways than it does now."

Overseas, Britain's luxury goods are in high demand. Professor Qing Wang found that 57% of Chinese shoppers said the royal warrant was "very important" in increasing the appeal of UK brands.