At least from a US perspective, the ability to “underreport your income when filling out your taxes” heavily depends on the source of that income. If your income derives from an on-the-books job, your ability to underreport income is nearly zero (although you can try for some phony deductions). If you’re self-employed or run a small business, your potential effectiveness is an order of magnitude greater—that 15 percent tax gap varies widely by type of income. I think variance in ability to evade seriously weakens some of your proposed benefits of evasion.
At least from a US perspective, the ability to “underreport your income when filling out your taxes” heavily depends on the source of that income. If your income derives from an on-the-books job, your ability to underreport income is nearly zero (although you can try for some phony deductions). If you’re self-employed or run a small business, your potential effectiveness is an order of magnitude greater—that 15 percent tax gap varies widely by type of income. I think variance in ability to evade seriously weakens some of your proposed benefits of evasion.