Wrong. Taxes were far higher on top incomes in the three decades after World War II than they've been since. And the distribution of income was far more equal. Yet the American economy grew faster in those years than it's grown since tax rates were slashed in 1981.
This wasn't a post-war aberration. Bill Clinton raised taxes on the wealthy in the 1990s, and the economy produced faster job growth and higher wages than it did after George W. Bush slashed taxes on the rich in his first term.
The economy requires sufficient funds on both the
supply side and the
demand side.
During the postwar years, we erred on the "Demand" side. Our tax, labor and trade policies were designed to put more money in the pockets of lower and middle class Americans. The wealthy were taxed at a much higher rate, and extra the revenue went to infrastructure, technological advances (which came in large degree through Cold War military spending) and a whole network of programs designed to reduce the middle class cost of living, e.g., affordable college. There was also a strong support for unions, which served to keep wages and benefits high. There was an alliance - albeit an uneasy one - between capital and labor. The result was that middle class Americans participated in the most robust economic growth this nation has ever seen.
And so yes, postwar policies gave the non-wealthy massive purchasing power. And guess what happens when consumers have more spendin' money? Investment capital pours in from everywhere to capture those consumer dollars. It's called a virtuous cycle. Indeed, the capitalist is forced to add jobs and innovate because consumers have a ton of extra money with which to buy whatever is produced. This also creates more competition because the market can support multiple suppliers across different consumer niches.
But the great postwar boom stalled in 1973 when we started to see high inflation and high unemployment (stagflation). This crisis, precipitated by what looks like a very strategic oil shock, breathed life into the once-obscure Supply Side movement, which held that high taxes and high labor costs created a disincentive to invest. (This makes sense, e.g., if my potential profits are usurped by high labor costs and high taxes, than I have less incentive to invest)
So we listened to the Supply Side movement and elected Reagan who curbed the excesses of the Welfare State and restored profit margins. He waged war on unions and made it easier for capital to flee expensive US labor for cheap labor markets around the globe. This is when we started to see the shift of production to China and other parts of the 3rd world.
Of course this had the effect of lowering American wages. In addition to the loss of good jobs (to sweatshops in China and Taiwan), Reagan waged war against the broad policy structure that boosted middle class purchasing power. To make up for lost jobs, Reagan lorded over the most aggressive expansion of credit in American history. Essentially, he replaced wage-based spending with debt-based consumption. The low wage structure boosted profits and temporarily spurred investment. Indeed, the steroidal expansion of credit repaired our 70s malaise and restored consumption to postwar levels. It was called Morning in America. And the economy grew at an impressive clip. But now the middle class has finally bumped into its borrowed-against future... and the nation is too indebted and lacks the job base and wage structure to consume at the needed levels to sustain economic growth.
The middle class feels less secure than at any time in history. Meaning: the jobs are gone and they are increasingly fleeced by government protected monopolies. Welcome to the rentier class that Adam Smith and Karl Marx warned about.
Now, the only jobs that come back to the USA are ones that underbid the 3rd world.
In short the game is over.
You can't sustain long term economic growth by replacing wages with credit (debt). Unless the middle class is solvent enough to consume, we will continue to see a very crisis ridden form of capitalism. But this has always been a flaw of capitalism. In its drive to lower the cost of production, capitalism cannibalizes its consumers by lowering their wages. And then it tries to make up for lost wages and slashed benefits by making it easier for strapped consumers to go further and further into debt. This always ends poorly.