Tax Cuts and Private Saving

We have already conducted most of the analysis we need to examine the effects of tax cuts on saving. We know that a tax cut increases disposable income. Our theory of consumption smoothing tells us that households will respond by increasing consumption and savings. Specifically, we predict that a dollar’s worth of tax cuts will cause saving to increase by (1 − marginal propensity to consume).

It is tempting to conclude that tax cuts therefore will lead both to higher consumption, increasing output now, and to higher saving, increasing output in the future. Such an argument is not right because it looks only at saving by households. We also need to look at the effect of the tax cut on the government surplus or deficit.

Tax Cuts and National Saving

If the government is spending more than it receives in tax revenues, then it is running a deficit. Conversely, if it is spending less than it receives in tax revenues, it is running a surplus. National savings is the combined savings of the government and the private sector. If the government is running a deficit,

and if the government is running a surplus,

These are just two different ways of saying the same thing because, by definition, the government surplus equals minus the government deficit.

What happens if the government cuts taxes? If there are no associated changes in government spending, then tax cuts translate dollar for dollar into the government budget. One million dollars worth of tax cuts will increase the deficit (or decrease the surplus) by exactly $1 million. So even though a tax cut of a dollar increases private savings by $(1 − marginal propensity to consume), it costs the government $1. The net effect (to begin with) is to reduce national savings by an amount equal to the marginal propensity to consume.

If the tax cut succeeds in increasing income, there is additional savings resulting from the multiplier process. Still, we expect the overall effect is a decrease in national savings. For example, consider the Kennedy tax cut again. Taxes were cut by $10 billion. The resulting change in income was roughly $20 billion. With the marginal propensity to save equal to 0.07, the offsetting increase in private savings would have been about $1.4 billion. Evidently, the result was a large decrease in national savings.

Here we see one of the biggest problems with tax cuts. They are attractive in the short run because they stimulate aggregate demand and increase output. They are also attractive politically, for obvious reasons. Unfortunately, they have the adverse long-run consequence of reducing national savings. When national savings decreases, the economy does not build up its capital stock so quickly, so future living standards are lower than they would otherwise be.