The sports-related expense of hosting in the British capital is likely to cost more than twice the original estimate, researchers from the university’s Said Business School said in a paper. That’s the most since the 1996 summer Olympics in Atlanta, when costs overran by 147 percent.

"The Olympics overrun with a 100 percent consistency,” Bent Flyvbjerg, who co-authored the research, said in an interview. "You reach a point of no return seven years before the games where you commit to delivering and writing this blank check. You can’t trade off time with money in the Olympics.”

London beat Paris and New York to host the games, which begin July 27. The U.K. government tripled its first budget to 9.3 billion pounds ($14.5 billion) after failing to get companies to finance and develop the main site. The security budget doubled to 553 million pounds last year as a review found that an original estimate of 10,000 guards was short by nearly 14,000 people