Michael Sullivan did very well as general president of one of the country's biggest trade unions -- the Sheet Metal Workers' International Association AFL-CIO -- during the last decade, seeing his pay triple and then some, to more than $1 million annually.

Robert Scardelletti, international president of the Transportation Communications International Union AFL-CIO, didn't do quite as well as Sullivan, but still managed to get by while seeing his pay almost triple in the same period, to nearly $750,000.

Larry Weinberg and Joseph Hunt, general counsel of the American Federation of State, County and Municipal Employees and general president of the International Association of Bridge, Structural, Ornamental and Reinforcing Iron Workers AFL-CIO, respectively, both saw their pay double as well.

The four topped total compensation calculations by The Washington Examiner for the 25 highest-paid public- and private-sector unions during the first decade of the 21st century. The calculations were based on data unions must report annually to the Department of Labor.

The average total compensation in 2011 for the top 25 union leaders was $569,750.

Between 2000 and 2011, these four union leaders were seeing eye-popping hikes in their compensation, inflation totaled 30.6 percent, according to USInflationCalculator.com.

Also during that period, the percentage of unionized U.S. workers declined from 14.9 percent to 13 percent, according to figures compiled by UnionStats.com, based on data from the government's Current Population Survey.

As a group, the top 25 union bosses saw their pay rise on average by 88.2 percent between 2000 and 2011. By contrast, compensation for corporate CEOs during that period decreased by 37.7 percent or 44.5 percent, depending upon whether stock options are included when given or when realized, according to data compiled by Lawrence Mishel and Natalie Sabadish for the Economic Policy Institute, a think tank funded in part by labor unions.

During the preceding two decades (1978 to 2000), however, CEO compensation increased 1,278 percent (1,390 percent with realized options), according to the EPI experts. Two of the largest economic expansions in the nation's history came during those years, under Presidents Reagan and Clinton.

Even so, contends American Enterprise Institute research fellow Aspen Gorry, there were two recessions during the decade ending last year, so "the compensation among top-paid union officials has held up surprisingly well."

Sullivan's 340 percent increase boosted him to the top of the list of highest-paid union officials just before he retired earlier this year. More than $778,000 of his 2011 total, however, reflected a one-time lump-sum payment he received from the union on retirement, a union spokesman said.

Scardelletti was the third-highest-paid, while Hunt ranked sixth. Weinberg was 11th at the time of his retirement last year.

Only one union leader in the group, Randi Weingarten, president of the American Federation of Teachers, experienced a decline in total compensation, at 5.6 percent, for the period.

Concerning Hunt's compensation, the current ironworkers union head said the membership approved it twice.

"General President Emeritus Hunt did an outstanding job leading our union through a tumultuous decade and was rewarded for those efforts by the democratically elected delegates of our membership during the Conventions of 2001 and 2006," said Walter Wise, general president of the union.

Representatives for Scardelletti and Weinberg did not respond to requests for comments.

Chris Edwards of the Cato Institute pointed to the contrast between the union chiefs’ increasing compensation and wage earned elsewhere in the national economy.

The average private sector wage in the U.S. grew 38 percent between 2000 and 2011, reaching an average of in 2011 of $53,463, Edwards said.  Average federal, state, and local government worker wages in the U.S. in 2011 were $59,229.

“Once unions sink their teeth into a workplace, it’s very difficult to dislodge them, which allows union leadership to behave in ways counter to the interests of their members,” he said.

“The solution is voluntary unionism, which would allow all workers to join unions or not, which would force union leaders to compete against each other to generate value for their members.”

Mark Tapscott is executive editor of The Washington Examiner.