The experience of the 1920's (for which I am taking the author's word) has not been repeated since we replaced 'tax-and-spend' with 'borrow-and-spend'. The resultant parabolic increase in debt has generated a huge increase in the valuation of assets, a vortex of hyper-prosperity among those with money to invest. That, coupled with steady increases in spending by government funded by debt, has ensured a trickle of money to flow to people who do not have an excess of it that they can 'afford to lose'. Just look at the change in the distribution of incomes since 1980. Whether "trickle down economics" is a formal theory or not, a 'trickle down economy' is what we now have.