Entrepreneurial optimism describes a specific, well-documented gap: business owners generally know the accurate statistical survival rate for businesses like theirs, and simultaneously rate their own personal chances of success far higher than that statistic — holding both the accurate general knowledge and the wildly optimistic personal exception at the same time without apparent contradiction. This isn't ignorance of the odds; it's a specific failure to apply general odds to oneself.
Kahneman notes this particular bias is genuinely double-edged: at the individual level, it likely leads to real financial harm for a share of the people who believe they're the exception and aren't, but at a broader economic level, this same widespread overconfidence is part of what drives the sustained risk-taking that produces genuine innovation and economic dynamism — a case where an individually costly bias may be collectively productive.