If you have flat income tax and BI, the net result is much the same as progressive tax and no BI.<p>Consider a BI of 100 with flat tax of 45%, and people with before-tax paychecks of 300 and 1000. First guy ends up with 265, second guy with 650. These exactly correspond to BI-less tax rates of 12% and 35% respectively. Second guy&#x27;s taxes can pay for both their BI and then some. Their paid taxes total 485, just short of 5 BIs worth.