Effective audit policy for voter-verified paper ballots

Scientists and politicians are reaching consensus that elections must be countable independently of the need to trust the computer software in a DRE voting machine or in an optical scanner. Public trust in elections requires a Voter-Verified Paper Ballot (VVPB), printed by a DRE or scanned by a scanner. But producing the VVPBs is not enough; to do any good they must also be audited. A recount of 1% of randomly selected precincts (as performed in some states) is not sufficient to detect fraud with high confidence, except in statewide races. A recount of 5% would be barely adequate, but would be quite expensive. I propose a new statutory framework that will be as affordable as a 1% recount but more effective than a 5% recount. It requires a mandatory audit of 1% of precincts, and permits any candidate to demand (and pay actual costs for) an audit of up to 7 precincts. The rule of 1%+7 will give high confidence for both large and small elections.