Except that in reality, lower average propensity to consume (APC) results from significantly increased real income.1 Who has how much matters because people tend to spend different portions of their income at different levels of wealth. Wealth and income distributions make a significant difference to effective demand. We're not concerned with what people would like to have if they had enough money; we're concerned with what people will spend with the money they're getting. If Warren is a wealthy person and John is a poor person and over time Warren attains a higher share of the available money, total spending -- effective demand -- generated by those two consumers will drop.
If there's $1,000,000 of total income between the two at time T1 and Warren gets $950,000 while John gets $50,000 and Warren spends 33.33%2 of income to John's 100% of income, then total spending by these two individuals at time T1 will be:
T1: $316,635 + $50,000 = $366,635.00When income ratios shift and there's an inflation-adjusted $1,000,000 of total income at time T2 and Warren gets $975,000 while John gets $25,000, Warren's spending ratio (APC) will likely have fallen slightly from the previous propensity, but we'll stick with 33.33% for simplicity and understatement. Meanwhile, John can't spend as much as before because John's available funds have dropped. Even if Warren still spends at the same rate -- which is unlikely -- then total spending would be:
T2: $325,967.50 + $25,000 = $349,967.50That would be a drop from time T1 to time T2 of $16,667.50 in inflation-adjusted spending. I've picked an arbitrary APC for Warren, but herein we're just showing the rough effect. The dollar values are merely for illustration of the concept. Even if the exact average amount might vary slightly from the $16,667.50 of our illustration, the point remains that there would be a shortfall. With more of the money shifted to those with a lower APC, you get lower consumption which is to say lower effective demand.
Even if total income increases, with enough shift from those who will spend higher percentages of their income to those who will spend lower percentages of their income, total spending can fall. More total wealth does not necessarily translate to more total spending. More total wealth will only increase total spending when distribution among varying APCs (and thus the overall APC) remains sufficiently stable. Having wealthy people is useful; but we need enough money in the hands of average consumers to support that wealth. Concentrate too much of the available wealth into too few hands and you get less ability to consume which means less effective demand.
Confronted with that reality, the "money is money" crowd rely on APC's flip-side, average propensity to save (APS). They're two sides of the same coin. As APC drops, APS rises. Our hypothetical Warren has a lower propensity to consume but a higher propensity to save. Some try to claim that the reduction in APC would be balanced out in terms of economic activity by the corresponding increase in APS. Unfortunately, that would only hold true in a closed economy with no outlets for investment other than productive investments (such as business start-ups and expansions). We're not a closed economy, so even when increasing APS does translate the savings into productive investment, those investments need not necessarily be domestic. For the United States, given that foreign returns are out-pacing domestic returns from such investments, much of the savings naturally translates into foreign investment which does absolutely nothing to balance out the reduction of consumption in our domestic economy.
Even if we were a closed economy, we have a variety of investment options beyond just productive business investments alone. For instance, Warren might buy gold ETF shares from Glenn who might then use the proceeds to speculate on the British Pound or perhaps to buy Treasuries.3 A dollar of savings lacks any certainty whatsoever that it would spur even a penny of business investment. Particularly when many businesses are avoiding expansion because they already have more than enough capacity to meet projected demand for their goods and services for the next several years, we find ourselves in a situation where there is both a shortage of effective demand from consumption and a shortage of available productive investment options due to insufficient need to expand caused by that same shortage of effective demand.
This all matters because we need a certain level of effective demand in order to sustain full employment. Without sufficient consumption, businesses need fewer workers. With less demand for labor, wages fall. Dropping wages and employment both further depress the nation's ability to consume, leading to yet more unemployment and dropping wages. With too much of our wealth concentrated at the top, we can't support as much wealth. That's bad for rich and poor alike. As Franklin D. Roosevelt said, "we all go up, or else we all go down, as one people." We as Americans believe in promoting wealth and affluence. But to do so effectively, we must have enough of a strong base underneath the top to support a growing top. To have steadily growing affluence, we must mitigate the divergence of our most wealthy from our lower and middle classes.
1. When the shift is initially happening, we refer to the marginal propensity to consume (MPC), essentially the rate of change in APC. Herein, we're not concerned with the rate of change but rather just the implications of such a change from one state of APC at one point in time to another state of APC at a second point in time.
2. The 33.33% and 100% value are arbitrary representations of the fact that higher income consumers spend less of their total income than lower income consumers. The actual observed multiplier for various income levels may vary. What's important here is not the specific percentages but rather the impact of the difference in percentages.
3. Treasuries arguably could indirectly contribute to productive domestic investment when the government spends within the economy. Likewise, the gold seller could use the proceeds to invest domestically. However, neither of these have the direct impact on domestic economic activity seen from domestic consumption or direct domestic business investment. They're not a clear proxy for domestic activity. They're a case where savings may or may not translate to investment.