“A study has found that software projects adopting Agile practices are 268 percent more likely to fail than those that do not.”
The 268% number comes from a five-day survey of 600 engineers, paid for by consultancy Engprax. The quoted expert is Dr Junade Ali, author of Impact Engineering, which happens to be the methodology the study recommends. Writing requirements down first makes projects 97% more likely to succeed. That part is true and nobody needed a sponsored survey to learn it.