A specter haunts the global economy, with the lingering prospect of another crisis that might throw the U.S. economy and others back into recession. Central banks and governments have worked to exorcise the specter, but their efforts have not eased anxieties. Nor have they addressed deeper systemic problems that make these economies vulnerable to banking sector risk. Uncertainty, heightened by a turbulent political year in America, casts a long shadow over the prospects for recovery. Mervyn King, former governor of the Bank of England, who led that institution through the financial crisis of late 2007 to 2009, addresses what went wrong…