To put that number in some perspective, $1.4 trillion is nearly equivalent to the entire economic output of Canada (US$1.6 trillion at last count).
Apple, Coca-Cola, Walmart, ExxonMobil and Google parent Alphabet are among the many companies with billions hidden offshore.
Apple alone has US$181.1 billion stashed offshore, the largest such stash listed in this report. General Electric has the second-largest stash (US$119 billion), followed by Microsoft with $108.3 billion.
"In addition to the 1,600 known subsidiaries, the companies may have failed to disclose thousands of additional subsidiaries to the Securities and Exchange Commission because of weak reporting requirements," the report said.
The report cited earlier research showing that offshoring of funds is costing the U.S. government some US$111 billion in lost tax revenue every year.
“From 2008 to 2014, the 50 largest U.S. companies collectively received $27 in federal loans, loan guarantees and bailouts for every $1 they paid in federal taxes,” the Oxfam report said.
The 50 companies earned $4 trillion in profit during that time, and used offshore accounts to help reduce their tax rate to 26.5 per cent, below the U.S.’s official (but rarely-paid) 35-per-cent corporate tax rate.
Oxfam also estimated that tax dodging costs poor and developing countries $100 billion annually, “preventing crucial investments in education, health care, infrastructure and other forms of poverty reduction.”
The report did not look at companies outside the U.S. A 2015 report from Canadians for Tax Fairness estimated Canadian companies had some $200 billion stashed offshore, at a loss of $7.3 billion annually to government coffers.
Oxfam's numbers come a week after the world was rocked by the release of the Panama Papers, a trove of 11.5 million documents linked to Panamanian law firm Mossack Fonseca, detailing hundreds of thousands of offshore accounts.
The revelations have touched numerous politicians and celebrities, including British Prime Minister David Cameron. Iceland's prime minister, Sigmundur David Gunnlaugsson, resigned over the issue last week.
Author: Daniel Tencer