What are the two important programs in practice in America that strongly resemble a negative income tax?

What will be an ideal response?

1. Food Stamps program: Food Stamp benefits decline as earnings rise, and Food Stamps are used like cash in many poor neighborhoods.2. Earned Income Tax Credit (EITC): As earnings rise from zero to some threshold, the federal government supplements the earnings of the working poor by giving them what amounts to a grant that is proportional to their earnings. But once earnings pass a second threshold, the government starts taking this grant back, just as a NIT would.