More private college presidents are millionaires.

Forty-two private U.S. college presidents made more than a million dollars in 2011 – up from 36 in 2010, according to a new report from The Chronicle of Higher Education.

Administrative bloat has long fueled public outrage about the cost of college. But astronomical presidential pay is largely a phenomenon of the post-2000 era, says Richard Vedder, director of the Center for College Affordability and Productivity at Ohio State.

“The base pay of these people is just the tip of the iceberg of what their total compensation is,” Vedder said, citing the perks of being a college president. "Whether those things get fully picked up or not, I don't know, but those have exploded, too.”

Vedder said Yale’s former president Richard Levin is a prime example of what’s become a troubling trend for many families struggling to pay tuition.

“When he was hired as president of Yale his salary was under $500,000 a year," Vedder said. "He’s now making $1.6 million. Same school. Same individual."

With inflation, Vedder admits, college presidents' salaries should continue to increase - just not so rapidly.

Two Boston-area private college presidents were among the 10 highest paid: Joseph Aoun, president of Northeastern Unviersity (No. 2, 3.1 million), and former Tufts University president Lawrence Bacow (No. 5, $2.2 million).

In recent years, presidential compensation has become more competitive as trustees increasingly tie presidential pay to certain outcomes like enrollment and fundraising.

Economists say there’s usually a trickle down effect to provosts and deans so that the president’s pay doesn’t get wildly out of line.