Wall Street lives on. One year after the collapse of Lehman Brothers, the surprise is not how much has changed in the financial industry, but how little. Backstopped by huge federal guarantees, the biggest banks have restructured only around the edges. Employment in the industry has fallen just 8 percent since last September. Only a handful of big hedge funds have closed. Pay is already returning to precrash levels, topped by the 30,000 employees of Goldman Sachs, who are on track to earn an average of $700,000 this year. Nor are major pay cuts likely, according to a report last week from J.P. Morgan Securities. Executives at most big banks have kept their jobs. Financial stocks have soared since their winter lows. Banks still sell and trade unregulated derivatives, despite their role in last fall's chaos. Radical changes like pay caps or restrictions on bank size face overwhelming resistance. Even minor changes, like requiring banks to disclose more about the derivatives they own, are far from certain. Regulators and lawmakers have spent most of the last year trying to save the financial industry, rather than transform it. In the short run, their efforts have succeeded. Citigroup and other wounded banks have avoided bankruptcy, and the economy has sidestepped a depression. But the same investors and economists who predicted, and in some cases profited from, the collapse last fall say the rescue has come at an extraordinary cost. They warn that if the industry's systemic risks are not addressed, they could cause an even bigger crisis - in years, not decades. Next time, they say, the credit of the United States government may be at risk.