Nearly three-quarters of callers to corporate whistleblower hotlines haven’t tried to take an issue to management first—and people who report corruption and fraud are actually less likely to seek anonymity than those who report other types of issues.

Those findings are just two of many in a first-of-its-kind benchmarking report recently released by The Network, CSO Executive Council, and the Association of Certified Fraud Examiners.

The groups analyzed nearly 200,000 hotline calls from more than 500 organizations across various industries over a four-year period. Among the other notable findings:

Investigations—A majority of hotline reports (65 percent) were serious enough to warrant an ...