"The optimal amount of fraud is non-zero."
No, the optimal amount of fraud is ZERO.
The cost of fraud detection and prevention is different, but in an ideal society, the taxpayers aren't paying for fraud (because the people don't scam the government).
If fraud detection is so expensive, maybe it's important to be more selective of who has access to the community and keep the scammers out.
If fraud detection is so expensive, maybe it's important to be more selective of who has access to the community and keep the scammers out.