Tax fairness activists rallied outside of the Walgreens downtown Chicago flagship store Wednesday morning in protest of possible plans by the nation's biggest pharmacy chain to move its corporate address from Illinois to Switzerland, a "tax haven."

Toting signs reading "Walgreens, don't shortchange America," about 20 activists called on Deerfield-based Walgreen Co. to remain an Illinois company and drop a potential plan to reincorporate itself offshore through a maneuver called a "corporate tax inversion." The move could cost U.S. taxpayers $4 billion in lost tax revenue over a five-year period, shows a new report released ahead of today's protest by Americans for Tax Fairness and Change to Win Retail Initiatives.

"If Walgreens relinquishes Illinois roots by becoming a Swiss company, it will not only be a betrayal of the people of the great state of Illinois, it will undermine critical taxpayer-funded services that we all rely on," stressed William McNary, co-director of Citizen Action/Illinois. "If Walgreens moves it corporate address offshore, it will still take advantage of all the benefits it gets from operating in America. It will still get the $72 billion in annual sales that we give them every year. It will still get the $16 billion that we as taxpayers give them for Medicare and Medicaid."

In 2012, Walgreen Co. also received $46 million in tax breaks over a 10-year period from the state of Illinois in exchange for job creation, the new report points out.

Under U.S. tax law, a so-called corporate tax inversion allows American firms to reincorporate in a foreign country when at least 20 percent of its stock is owned outside of the United States, according to the report.

If Walgreen completes its purchase of Switzerland-based Alliance Boots, Europe's biggest drug wholesaler and retailer, an inversion could become a possibility as early as next year, the report states. Walgreen already owns a 45 percent stake in Alliance Boots and will have the ability to buy the remaining 55 percent starting in February 2015, pending shareholder approval.

Several large hedge funds and Alliance Boots' Executive Chairman Stefano Pessina, who is also Walgreen's largest shareholder, are reportedly "driving the initiative" for an inversion, according to the report.

"There are no business performance reasons for Walgreens to change its corporate address to Switzerland. It’s a very healthy company with $72 billion in annual sales and $2.5 billion in profits," the report states. "In fact, none of the shareholders pushing for inversion appear to have cited any benefit to the company besides the reduction in its tax rate. Nor has the company, in its public statements on this issue, noted any reason for a move to Switzerland besides reducing its taxes."

Walgreen spokesman James Graham declined to comment beyond a statement he issued to the media in response to the report:

As we’ve said before, we continue to analyze a number of issues as we move toward the window for exercising the second step of our transaction with Alliance Boots, and we will do what is in the best long-term interest of our company and its shareholders.

The findings in the report by the Americans for Tax Fairness and Change to Win Retail Initiatives are based on estimates provided by three equity research firms, which have determined Walgreen's income tax rate could drop to 20 percent from its current rate of about 31 percent if the company shifts its corporate address to Switzerland.

A company that has completed an inversion does not have to pay U.S. taxes on its global income "if it has reincorporated in a country with a territorial tax system," the report states. In such an instance, a firm would only pay U.S. taxes on income earned in America. The original American firm becomes a subsidiary of the foreign parent company in the event of an inversion. However, shareholders of the original U.S. firm control the foreign company, the report explains.

Anna Wilson with ONE Northside said the estimated $4 billion loss in U.S. tax revenue through a Walgreen inversion could mean cuts to crucial services and programs involving infrastructure, education and social services. This could create "a climate that makes it even harder for people to get back on their feet again," she said.

"We're in a revenue crisis," she stressed. "It's time for corporations to pay their fair share. Our city, state and country deserve better from Walgreens since we have supported the company over the years ... and have made it what it is today."

Here's more from Wilson, McNary and scenes from the rally, which was organized by Americans For Tax Fairness, Citizen Action/Illinois, Change to Win Retail Initiatives, ONE Northside and UFCW Local 881:

Meanwhile, Walgreen also makes a quarter of its income from government-funded programs, according to the report's estimates. The company raked in $72 billion in sales in 2013, and 23 percent of that income, or $16.7 billion, came from Medicare and Medicaid, the report states. And over the past five years, U.S. taxpayers have also subsidized Walgreen's executive pay to the tune of $11 million through what critics bill as a loophole in the current corporate tax code, which allows unlimited corporate tax write-offs on performance-based compensation for top executives.

The corporate tax inversion maneuver is one of many examples illustrating how "broken" the U.S. tax system is, explained John Gaudette, organizing director with Citizen Action/Illinois.

"It's not that America is broke, it's that our tax system is broken," he said. "We have companies that are looking to leverage the American economy as much as they can to maximize their profit, which we think is unfair ... We all need to do our fair share to make sure that we can keep the economy thriving and growing."

President Barack Obama's 2015 budget proposal includes provisions to make corporate inversions harder for firms. Other measures targeting the tax trick, such as the "Stop Corporate Inversions Act of 2014" (S. 2360), also are pending in Congress.

"We need elected officials to close corporate tax loopholes and to stand up to the corporate greed that is rampant in America," said Hannah Gelder, an organizer with ONE Northside.

Gelder noted that the statewide coalition Fair Economy Illinois, of which ONE Northside is a member, has been highlighting corporations that are not "paying their fair share" and is pushing for state legislation that would close corporate tax loopholes and require corporate tax transparency.

"Two-thirds of corporations pay nothing in taxes to Illinois and 9 percent of the state's revenue comes from corporate income tax, whereas 55 percent comes from the individual income tax," she said. "There's a great discrepancy in where the revenue is coming from. We believe we need a fair corporate tax code."