Chief executives of Washington’s most active trade lobby groups defied the sluggish economy and enjoyed pay increases averaging 16 percent.

Heads of the 30 top industry associations took home an average of $2.34 million in 2010, up from $2.02 million the previous year, according to tax data. Those groups have spent $1.67 billion in Washington lobbying since Barack Obama entered the White House, with the U.S. Chamber of Commerce accounting for one-third of that amount.

“The nature of their core activity is recession-proof,” said Marcus Owens, a partner at Caplin & Drysdale, a Washington law firm, and former director at the Internal Revenue Service, where he oversaw cases on tax policy and nonprofits. “Even in a recession, the government continues to make decisions.”

The analysis showed a significant gender gap on compensation, with the four female CEOs on the list of 30 executives trailing their male counterparts by more than $1 million in base pay, incentives and deferred compensation.

The four women in the group took home on average about $1.43 million in total pay, compared with the $2.48 million pocketed by the 26 men. That means they earned 57 cents for every dollar paid to their male peers.

The industry groups were ranked by the amount they spent on lobbying in the first three years of the Obama administration. That list captures trade groups that have spent more than $17.5 million influencing policy in Washington since 2009.

Lobbying expenses grow

As lawmakers debated the president’s health-care proposal, expenditures from the 30 largest trade lobbies reached $663 million in 2009, compared with $449 million spent the year before. Spending slowed to $586 million in 2010 and $420 million last year, according to an analysis of data from the Washington-based Center for Responsive Politics.

Former lawmakers who have walked through the revolving door into Washington lobbying have fared best as a group.

The 10 retired officeholders on the list who served in their jobs over at least two fiscal years between 2008 and 2010 earned total average compensation of $2.72 million. This subgroup includes eight former members of Congress and two retired governors: Frank Keating, 68, of Oklahoma, and John Engler, 63, of Michigan.

Billy Tauzin, a Republican former congressman from Louisiana, led all trade group heads with $11.6 million in total compensation in his last year at the Pharmaceutical Research and Manufacturers of America, a 152 percent jump from 2009. His base salary constituted $1.11 million of that total.

Ranked just behind Tauzin, 68, in total pay were two executives who haven’t served in office: Jack Gerard, 54, who earned $6.4 million at the American Petroleum Institute, and the Chamber’s Thomas Donohue, 73, who took home $4.75 million. Gerard’s 2010 salary was 49 percent higher than his pay for the previous year, and Donohue’s salary jumped 27 percent over the same period.

Engler, who served as president and chief executive of the National Association of Manufacturers before taking his current position as president of the Business Roundtable last year, says high salaries are justified.

People who have served in public office have unique skills, and “the market is competitive,” Engler said in an interview in Washington. He earned $1.44 million at NAM in 2010, and his 2011 Business Roundtable salary has yet to be disclosed.

An Obama critic

Donohue has been a prominent critic of the Obama administration, saying its regulatory efforts have curbed economic growth. The Chamber spent $30 million in the 2010 midterm elections, all but about $2 million to elect Republicans, according to Federal Election Commission reports.

“We’re engaging earlier and more aggressively than ever,” Donohue said in a Feb. 9 statement. “We’re asking the public to hold members of Congress accountable for their positions on Obamacare, job-killing regulations, energy security, and a culture of wasteful spending in Washington.”

David Chavern, the Chamber’s chief operating officer, who had $1.1 million in total compensation in 2010, said Donohue’s salary is justified by the leadership skills he has displayed since taking the job in 1997.

“The list of people who could do what Tom does is exceedingly small, and it should come as no surprise that our board tries to compensate him in a way that recognizes that,” Chavern said in an e-mailed statement.

R. Bruce Josten, the Chamber’s top lobbyist, earned $1.69 million, according to the group’s tax filing.

Carlton Carroll, an API spokesman, declined to comment on Gerard’s compensation, citing a policy on personnel issues.

Tauzin’s salary reflected, in part, his role in brokering a deal with the Obama administration capping at $80 billion the amount drugmakers would contribute to health care reform.

With salaries of members of Congress at $174,000—or 1.5 percent of Tauzin’s final payday — lawmakers can get tempted to look toward their post-government career, according to Jill Fisch, a University of Pennsylvania law professor who specializes in corporate governance.

“That’s the classic concern of the revolving door,” she said. “People take government jobs to get higher-paid positions in the private sector, and actions in the public sector are influenced by their possible next step.”

The analysis was limited to trade organizations charged with representing the interests of industries, and excluded single companies or pressure groups backed by individual paid members, such as the National Rifle Association and AARP, the largest advocacy group for older Americans. Salary figures were taken from Form 990 filings that nonprofit organizations are required to submit to the IRS and that list their highest-paid employees.

Twenty-six of the top 30 have completed their 2010 regulatory filings with the IRS disclosing executive salaries for that year. For the remaining four — the American Bankers Association, the Recording Industry Association of America, the Managed Funds Association and the Securities Industry and Financial Markets Association — Bloomberg analyzed 2008 and 2009 salary filings.

Peter Brusoe, Jonathan D. Salant, and Alexandre Tanzi in Washington contributed to this report.