US CEO salaries are increasing at the fastest rate in 14 years, raising concerns about the risk of worsening social inequality.

According to data compiled by ISS Corporate, a division of Institutional Shareholder Services, the average CEO salary at S&P 500 companies will increase by 12% by 2024. This is significantly higher than the 4.1% annual salary increase in the US according to official statistics.

This week, billionaire Elon Musk won a shareholder vote on a $56 billion pay package for himself.

William George, former chairman of the compensation committee on the board of energy company Exxon and former CEO of medical device company Medtronic, said Mr Musk’s victory sends a message to senior managers that “they can make as much money as they want.”

The rising pay for those positions is largely due to companies wanting to prevent their CEOs from accepting offers from competitors, said Robin Ferracone, CEO of consulting firm Farient Advisors.

Meanwhile, Mr George expressed “disappointment” at major investors, such as BlackRock and Vanguard, for not standing up against excessive CEO pay .

US CEO pay is rising at its fastest pace in 14 years, raising concerns about the risk of worsening social inequality.

BlackRock and Vanguard are Tesla’s biggest institutional investors and the world’s two largest asset managers. Both firms voted in favor of Mr Musk’s $56 billion compensation package last week.

According to the law firm Sullivan & Cromwell, only 1% of CEO pay votes at S&P 500 companies failed this year.

CEO pay “has gotten out of hand,” George said, adding that it would deepen the divide between rich and poor in the United States. This was a serious concern, he said, because it could fuel distrust in companies.