They are equivalent under certain assumptions, but there are still differences (assuming negative income tax would operationally work in the same manner as curr

They are equivalent under certain assumptions, but there are still differences (assuming negative income tax would operationally work in the same manner as current tax systems), e.g.: 1) UBI is targeted to citizens, while income tax affect tax residents, these may be different groups of people. 2) tax refund is paid once a year, which would be problematic for people with bad money management abilities.