system
Given the following post, respond as if you're commenting on Reddit:
human
What are the functional differences between a Universal Basic Income, Negative Income Tax, and a Guaranteed Minimum Income?
gpt
Sometimes those terms are used interchangeably.. and sometimes each type has different models of how it operates..

But generally, Universal Basic Income is a flat amount granted to every individual regardless of income..
For example, every citizen receives $1000 per month..

With Negative Income Tax people below a certain level get a stipend that is based on a percentage of the difference between a threshold amount and ones income level..
For example, if the threshold amount is $20,000 and someone earns $10,000 and there is a negative income tax rate of 25% that person would get $2500 added to their income.. 

Guaranteed Minimum income is a lot looser to define and can entail many different kind of strategies. Ultimately there is some kind of minimum level of income identified and only people who qualify in some way receive the benefit/transfer or whatever you want to call it.