An Analysis of Corporate Inversions.

"Summary U.S. multinational corporations—businesses incorporated and operating in the United States that also maintain operations in other countries—can use a variety of strategies to change how and where their income is taxed. One such strategy is a corporate inversion, which can result in a significant reduction in worldwide tax payments for a company. U.S. companies have engaged in corporate inversions since 1983, and public and government attention to them has varied over the years. Concern grew most recently in 2014 because the group of corporations that announced plans to invert that year included some that were very large: Their combined assets were $319 billion, more than the combined assets of all of the corporations that had inverted over the previous 30 years.

What Is a Corporate Inversion?
A corporate inversion occurs when a U.S. multinational corporation completes a merger that results in its being treated as a foreign corporation in the U.S. tax system, even though the shareholders of the original U.S. company retain more than 50 percent of the new combined company..."
Corporate Inversions