When big corporations use offshore tax havens, small businesses pay the price -- literally. If they were to cover the cost of corporate abuse of tax havens in 2011, the average U.S. small business would pay $2,116, according to a report released Tuesday by consumer group U.S. PIRG. The estimate is based on Census numbers for businesses with fewer than 100 employees.

"When corporations shirk their tax burden by shifting profits legitimately made in the United States to offshore tax havens like the Caymans, the rest of us must pick up the tab through either cuts to public spending priorities, higher taxes, or more debt," Dan Smith, tax and budget associate for U.S. PIRG and one of the report's co-authors, said in a statement. "Responsible small businesses are further hurt by corporate tax dodging because they are put at a competitive disadvantage since they can't hire armies of well paid lawyers and accountants to use offshore tax loopholes."

Small-business owners spoke out at a press conference on Capitol Hill Tuesday for the release of the report. "While I'll be paying my taxes -- investing in the public infrastructure and services that underpin our economy -- many profitable large corporations will be paying a lower tax rate than me or not paying taxes at all," Joseph Rotella, owner of Spencer Organ Company in Waltham, Mass., said. "That puts small businesses at a competitive disadvantage and undermines our nation. We need to stop the tax haven abuse that lets big corporations avoid paying their fair share and gives them an unfair advantage in the marketplace."

Aimee McQuilkin, owner of Betty’s Divine, an independent clothing boutique in Missoula, Mont., said corporations that use tax loopholes are "robbing our country of the revenues we need to invest in our future and support small businesses. If you want to fly the American flag outside your corporate headquarters, you should pay your way."

The U.S. Treasury loses an estimated $100 billion a year due to tax haven abuse, with $60 billion of that being tax avoidance by U.S. corporations, according to a Senate investigation. Another study by the GAO found that at least 83 of the top 100 publicly traded corporations use offshore tax havens.

According to a recent survey of 500 small-business owners nationwide conducted by American Sustainable Business Council, Main Street Alliance and Small Business Majority, nine out of 10 small-business owners said U.S. multinationals' use of loopholes to shift profits to offshore subsidiaries to avoid taxes is a problem. Meanwhile, three-quarters said their small business is harmed when loopholes allow big corporations to avoid taxes, and more than two thirds believe big corporations are not paying their fair share of taxes.

Rep. Chris Van Hollen (D-Md.), a co-sponsor of the Stop Tax Haven Abuse Act (H.R. 2669), also attended the press conference. "The simple fact of the matter is this: tax breaks for Big Oil, corporate jets, and companies that send jobs overseas have the practical effect of raising taxes on everyone else," Van Hollen said. "That's not right. That's not smart. That's not fair. And it's high time we do something about it."