4-FLEXIBILITY (ADAPT TO ECONOMIC CONDITIONS) 5-BENEFITS RECEIVED (BENEFIT FROM THE SPENDING OF THE MONEY COLLECTED THROUGH THE TAXES) 6-ABILITY TO PAY TYPE OF TAXES 1- PROGRESSIVE : THE RATE (%) INCREASES AS THE INCOME INCREASES. (Ex. FEDERAL INCOME TAX). 2- PROPORTIONAL : SAME RATE TO EVERYONE. 3- REGRESSIVE : TAKE A