TAX RATES WERE SLASHED DRAMATICALLY DURING THE 1920S, DROPPING FROM OVER 70 PERCENT TO LESS THAN 25 PERCENT. WHAT HAPPENED? PERSONAL INCOME TAX REVENUES INCREASED. DESPITE THE REDUCTION IN RATES,REVENUES ROSE FROM $719 MILLION IN 1921 TO $1164 MILLION IN 1928, AN INCREASE OF MORE THAN 61 PERCENT. WHAT HAPPENED NEXT? THE GREAT DEPRESSION (1929-39) WAS THE DEEPEST AND LONGEST-LASTING ECONOMIC DOWNTURN IN THE HISTORY OF THE WESTERN INDUSTRIALIZED WORLD.