German Chancellor Angela Merkel has pledged to fight for a global tax on financial markets at the next G20 meeting

German Chancellor Angela Merkel has pledged to fight for a global tax on financial markets at the next G20 meeting in Canada in June. Her favored tool is what's called a transaction tax, originally proposed by economists back in the 1970s on currency trades. She'll face an uphill struggle to push it through internationally, but the idea has some enticing advantages.