From The Economist:
The most elegant solution comes from Joshua Ronen, a professor at New York University. He suggests "financial statements insurance", in which firms would buy coverage to protect shareholders against losses from accounting errors, and insurers would then hire auditors to assess the odds of a mis-statement. The proposal neatly aligns the incentives of auditors and shareholders—an insurer would probably offer generous bonuses for discovering fraud. Unfortunately, no insurer has offered such coverage voluntarily.