The second type is a public charity, in which the donor gives up all rights to control and direct the charity’s investments and gifts. In exchange for that loss of control, the donor can deduct as much as half of their annual income in future years, as opposed to 30 percent for donations to private foundations.

Tax Deductions

The George Kaiser Family Foundation is a type of public charity known as a public foundation. It isn’t obligated to donate a penny, according to IRS rules. In 2003, the year it purchased the Excellence, it gave $677,000 to public causes, about one-10th of one percent of its assets, according to its tax return for that year.

“It is perfectly clear that Congress has established a public policy that there be no minimum distribution for public charities of our kind,” Dorwart said. “Someone who is articulating that criticism is criticizing the law.”

The charity gave away $302 million from 2002 to 2011, according to data compiled by Bloomberg. Kaiser, who has a net worth of $13.5 billion, according to the Bloomberg Billionaires Index, donated $3.12 billion to the charity during the period. He could have claimed enough personal income tax deductions to sidestep hundreds of millions of dollars in personal federal taxes, according to Richard Sills, senior partner for tax-exempt organizations with Holland & Knight LLP in Washington, D.C.

Tax Havens

Kaiser declined to comment through spokesman C. Renzi Stone, who referred inquiries to the charity’s executives.

Some of the foundation’s investments are based in corporate tax havens, such as Mauritius, Ireland and Belgium, allowing it to avoid U.S. corporate taxes because businesses not central to a charity’s mission can be subject to levies, according to IRS regulations.

Executives from Kaiser’s for-profit companies also manage some of the charity’s investments, an activity that is forbidden in a private foundation structure, according to Bruce R. Hopkins, senior partner at law firm Polsinelli LLP in Kansas City, Missouri, and author of more than a dozen books on charitable organization tax issues.

Unusual Charity