" Several experts in nonprofit accounting and governance told Fortune it was difficult to assess the validity of Buffett’s criticisms based on publicly available financial statements and tax forms. Common metrics for assessing bloat regarding administrative expenses and grant-making efficiency, they said, met or beat common benchmarks.

“I don’t think we can understand what [Buffett] knows as an insider,” said Karen Kitching, a professor at Georgetown’s McDonough School of Business.

Gates Foundation staffers are well-paid, receive generous benefits and travel frequently to conferences and events, noted Jesse Lecy, a professor in data science and nonprofit studies at Arizona State University.

“These practices might be interpreted by some as bloat, but it could also be interpreted as investments in a highly competent and professional staff,” he wrote in an email to Fortune."

msn.com - Warren buffett s friendship with bill gates has soured what that means for the billion gates foundation