Interest rates on Italy’s debt have soared to dangerously high levels, as bond yields hit 7.4 percent – the level that has driven other euro zone countries to seek bailouts. In comparison, Germany’s interest rates stand at just 0.24 percent. Wednesday’s news comes just a day after Prime Minister Silvio Berlusconi pledged to step down on the condition that Parliament pass an austerity budget required by the European Union. Uncertainty over whether Europe’s third largest economy will be able to meet its fiscal challenges will continue to test world markets. Louise Story, Wall Street and finance reporter for The New York Times, examines Italy’s impact on the world economy.