What could explain why a decrease in taxes could lead to a less-than-proportionate increase in output? a. as a result of diminishing returns to current consumption, consumers may choose to spread the extra spending over the long term rather than consuming the proceeds of a tax cut all at once. b. consumers may choose to save much of the tax cut in anticipation of having to pay higher taxes in the future. c. a decrease in taxes will necessitate lower government outlays, thus largely offsetting the higher consumption expenditures of households. d. all of the above. e. a and b only.