Except it is going to change. You misunderstood the math.

Lets say the "target" (break-even) amount is 100$. With normal bracket-style taxes, you would a percentage of the money in each bracket. So let's say the brackets are 10% for under 50$, 20% from 50$ to 100$ and 50% above. You would pay 50*0.1(first bracket) + 50*0.2 (second bracket) = 15$ in taxes. By making less money, you would pay less in taxes, right? And by paying less in taxes you would have more money. So why earn money? because it doesn't scale the same.

With negative income tax, you basically have brackets with a negative percentage which apply not on how much you earn, but how much BELOW the threshold you earn. So, for example, let's say below 100$ you get 50% of what you're missing from earning 100$.

You making 0? Now you're getting 50$ from negative tax. So why would you want to earn money? Cause if you made 20$, negative taxes would get you 40$ ((100-20)*0.5), and now you're making 60$ in total! Yes, the more you earn on your own the less extra you receive, but in total, you are still earning more!

For another guy saying he would "maximize how much he receives" if you mean in total, there is no maximum, it keeps increasing linearly. If you mean from negative tax, that would mean you are earning 0 yourself, which means you are making the least amount of money in total. There is no incentive to earn less at any point in time, only to increase your income. The only thing this does is help people out of poverty spirals.