The nation of Mali has two income tax brackets — 3% and 30%. Which one would you fall in? That’s entirely up to you.
People registering at the tax office are simply told, “You have the choice between two income tax regimens, 30% or 3%, which shall it be?”
As it turns out, no one expects anyone to choose the 30% option. By having a choice, it makes people think they are getting a bargain, so they are less likely to complain and will be more likely to pay what they owe.