You might think that a massive financial collapse that imperiled the nation’s economy, cost taxpayers billions, and destroyed further billions in wealth might be fertile ground for prosecution. But two and a half years after Lehman Brothers collapsed, few CEOs or other officials have been called to account—unlike, say, the 1980s savings and loan crisis. Reduced funds for key law enforcement offices, worries in government circles that prosecutions could imperil the nascent recovery, and just plain timid behavior on the part of regulators combined to produce little accountability, experts say. “It’s consistent with what many people were worried about during the crisis, that different rules would be applied to different players. It goes to the whole perception that Wall Street was taken care of, and Main Street was not,” said David A. Skeel, a law professor at the University of Pennsylvania.