Care of Elliott Clarke at Westpac:
Ever since the GFC (if not many years before), financial conditions and taxation in the US has favoured wealthy households. On financial conditions: the ownership of property is heavily skewed towards the wealthy; the same can be said of stock holdings, both those held directly (which depend on existing wealth) and via pension accounts (a function of current income).
These are the individuals who’s wealth has risen the most postGFC and who have also been able to take most advantage of favourable tax treatments – the deduction of state & local taxes and mortgage interest from Federal taxable income and favourable capital gains taxation to name a few.