MR. HUBBARD is hardly the only marquee economist to parlay his experience and stature into millions of dollars, for speeches, papers and expert witness testimony. Lawrence H. Summers, once the Obama administration’s top economic adviser, pocketed about $5.2 million in compensation for giving advice to a hedge fund. But in Mr. Hubbard’s case, some of his amply compensated work takes policy stands that buttress the viewpoints of the corporate interests that are paying him.

That’s been true of the mutual fund industry, which has paid him more than $1 million over the years. In an academic paper and a book, he took a strong position favoring the industry’s approach to fees, which critics say hurt everyday investors. He was paid what he called an honorarium of $150,000 for the academic paper by the insurance arm of the Investment Company Institute, the mutual fund industry trade and lobbying group.

“Dean Hubbard is a mercenary,” says John P. Freeman, emeritus professor of business and professional ethics at the University of South Carolina School of Law, who has accused the mutual fund industry of profiteering, “out to protect fund managers who are taking advantage of investors.”

Mr. Hubbard says the source of funding is irrelevant because his academic writing stands on its own.

Some of Mr. Hubbard’s extracurricular activities have also made faculty members at his Columbia Business School unhappy, because, they say, they reflect poorly on the institution. Others complain that he has run the school with a somewhat autocratic hand and feel that they have been buffaloed into casting votes and rallying behind causes that they haven’t necessarily supported.

One of those causes was Mr. Hubbard himself. It’s been a well-kept secret, but faculty members say that in 2008, the president of Columbia, Lee C. Bollinger, wanted to bounce Mr. Hubbard from his job. Why? Nobody has offered an explanation, not even to the senior faculty members who were asked at a meeting to rally behind their leader by signing a petition of support. Neither Mr. Hubbard nor Mr. Bollinger would answer questions on the subject.

Mr. Hubbard’s friends and fans note that he is a conservative leading an institution dominated by liberals, and that some friction is inevitable. As for calling Mr. Hubbard a mercenary — that suggests that he will fight for causes he doesn’t believe in. Which, one former colleague says, is not so.