In mortgage lending there are NINA loans - No Income No Asset verification! There are legitimate secondary market products which charge a higher rate. Underwriting guidelines generally require that while there is no verification, that the credit score be higher, no recent delinquencies, etc., no gifting of funds and the loan to value is lower than conventional products.
There are also stated income products (basically the same information), except that the underwriter can run ratios. U/W looks for income history (e.g. same job for 2 years or self employed 2 years same business & location) and continuation (social security awards letters are reviewed with amounts blacked out.) Higher rates are charges and credit scores must also be higher (usually 700+ FICO range).
It is significantly riskier, and most U/W would rather not underwrite those files. However - they are (pretty much) standard and accepted in the secondary market.
Integrity. With it, nothing else matters. Without it, nothing else matters.