For years, celebrity babies have been big business. Photos of them sell magazines, spur clothing trends, and even keep their famous parents in the tabloid news cycle.

Take North West, the newest addition to the Kardashian Klan, daughter of Kim Kardashian and Kanye West. North was the subject of nearly half a million tweets in the week following her birth on June 15, according to Topsy, a company that measures and analyzes social media. Kardashianâs pregnancy was the topic of endless magazine covers, with headlines from âI Canât Stop Eating!â to âDonât Call Me Fat!â to âThis Baby Is Ruining My Lifeâ and âPregnant & Alone.â But the biggest retail-churning effect is ahead. The familyâs reality show life will likely make North a new small-screen stalwart, much like Kourtney Kardashianâs children. Her son Masonâs clothing choices are chronicled, as is the brand and model of daughter Penelopeâs stroller.
But as much attention is devoted to North Westâor BeyoncĂ© and Jay-Zâs daughter, Blue Ivy, or any of the Jolie-Pitt children, for that matterâthe celebrity baby industryâs biggest star has yet to be seen. âWithout question, Kate Middletonâs pregnancy has been the most buzzed topic of the year,â said Jenny Schafer, senior editor at Celebrity Baby Scoop via email. âOne thing is for sure, the royal tot will be the most famous baby in the world.â
Due July 13, Kate Middleton and Prince Williamâs baby is expected to inject some $400 million into the British economy via parties, memorabilia, tourism, and even stroller sales. Middleton is arguably the most famous celebrity right now: using the same metrics we used to measure the influence of celebrity progenyâcoverage by the tabloid press, social-media presence, and public perception of influenceâshe comes out on top. The duchess has been on the covers of countless magazines around the world, from Marie Claire South Africa to The New Republic. Nearly every outfit she wears sells out instantly. Itâs not a stretch to predict her child will generate the same sort of attention.
Methodology
To figure out which celebrity children wield the most influenceâwhich we defined as having an effect on the publishing and retail industries, as well as the public persona of his/her celebrity parent (or, in most cases, celebrity parents)âwe considered several data-based metrics. We started with an initial list of more than 30 celebrity offspring who were 5 years old or younger as of June 1, 2013.
We then considered the following for the year starting June 1, 2012:
Internet presence: measured by the Google page results (weighted 20 percent).
Twitter mentions: measured by Topsy, a company that analyzes social-media trends and topics, which provided volume of Twitter discussion related of each celebrity baby (weighted 20 percent).
Tabloid presence: measured by the number of covers or partial covers devoted to the celebrity babies or parent(s). We considered People and Us Weeklyâthe two celebrity-focused magazines with a circulation of at least 1 million. (weighted 20 percent).
Public perception: measured by Celebrity DBI, a global celebrity evaluation index powered by REPUCOM, to provide influence and trendsetter scores for each celebrity parent. This score measures awareness and ability to have an impact on consumers. (weighted 40 percent).