Philanthropy is becoming a new status symbol for wealthy individuals in the United States as billionaires pledge large portions of their fortunes to charity. Experts note that being wealthy may now be defined by how much money one donates rather than material possessions. Warren Buffett and Bill Gates' Giving Pledge, which encourages billionaires to donate at least half their wealth, has inspired others and raised an estimated $150 billion in potential donations. While recognition is not the main motivation for most donors, some experts argue that philanthropy achieving status symbol status could still benefit charities by encouraging more giving from the wealthy.