Some of the largest U.S.-based companies are holding an estimated $1.9 trillion in earnings in offshore tax havens, thanks to a high corporate tax rate, the ease of shifting profits to low-tax countries, and the ability to defer taxes until profits are brought home. According to a study of some 83 countries by Bloomberg, General Electric leads all U.S. companies, with $108 billion held offshore. Pfizer comes in second, at $73 billion, followed by Microsoft, Johnson & Johnson and IBM. Other companies, including Apple, Cisco Systems and Citigroup also sock considerable cash stockpiles offshore. This complicates efforts to reform the tax system, and to encourage these same companies to invest their cash in new offerings – and jobs.