In a Ford assembly plant in 1925, a worker could put together a car in a fraction of the time it had taken just a few years before. The machines were faster, the lines were smoother, the output per hour kept climbing. Across American industry through the 1920s, manufacturing output per worker rose by roughly forty percent. That's a staggering leap. Factories were producing more goods, with fewer hours of labor, than anyone had thought possible.
So here's the question that should nag at you. If each worker was producing forty percent more, where did all that extra value go? Because it did not, for the most part, go into their paychecks. While productivity surged, the wages of the people doing the producing barely moved. And that gap — between what workers made and what they earned — is the quiet fault line running underneath the whole Roaring Twenties.
That's what this section is built around: the demand problem hiding beneath the prosperity. An economy can look gloriously healthy and still be standing on a crack, because a boom that produces mountains of goods only works if the people inside it can afford to buy them.
Start with the gap itself, because it's the heart of everything. Output per worker climbed sharply through the decade. Real wages for most industrial workers, meanwhile, rose only slowly — far slower than productivity, and far slower than the profits the same factories were throwing off. The economist who studied this period most carefully, the British historian and Keynesian-school analysts who came after, kept circling the same uncomfortable arithmetic. The pie was growing fast. The slice going to ordinary wage-earners was growing slowly.
Think about what that means in plain terms. A factory finds a way to make twice as many radios per worker. Wonderful. But if the worker's pay stays roughly flat, then the worker can't buy twice as many radios. Someone has to. The extra output has to go somewhere — into someone's hands, someone's home, someone's purchase — or the whole machine grinds. And in the 1920s, the answer to "where did the gains go" was clear. They went up.
This is the part worth slowing down on, because it's where most people's mental picture of the twenties is fuzzy. The decade is remembered as broadly prosperous — flappers, jazz, a chicken in every pot, a car in every garage. And there was real prosperity. But it was distributed in a way that would alarm any modern economist. The share of national income flowing to the very top rose through the decade. By the end of the 1920s, the richest one percent of Americans were taking home close to a quarter of all income — a level of concentration the country would not see again until our own century. The top tenth of one percent — the truly wealthy, the industrialists and financiers — held a slice of national wealth that, measured against everyone below them, looks almost vertical.
Here's the cross-domain way to feel it. Picture a stadium at full capacity, and imagine you're handing out the decade's economic gains by seat. Most of the seats — the workers, the clerks, the farmers — get a few dollars apiece, barely more than they got the year before. But a single luxury box at the top gets handed a stack so tall it dwarfs the rest of the stadium combined. Everyone's technically "up." But the room is tilting.
Now — why did this happen? This is where it gets structural, and where the moralizing usually starts and shouldn't. It's tempting to say the rich were simply greedy, and leave it there. The deeper answer is about where the money went after it was made. Corporate profits in the 1920s were enormous, and a huge share of those profits got plowed back in — into new plants, new machines, new capacity, and into the stock market. Reinvestment and speculation soaked up the gains. What got starved was the thing the whole consumer economy actually depended on: purchasing power in ordinary hands.
So the structural problem is this. Too much of the decade's income went to profits and reinvestment, and not enough went to wages — to the broad consumer base that was supposed to buy all the cars and radios and refrigerators those reinvested factories were now capable of making. Bear with this for one more step, because it's the hinge of the whole argument. An economy built on mass production needs mass consumption to match it. You cannot build factories that can make goods for a hundred million people and then pay wages that let only the top few million actually buy them. The arithmetic does not close.
This is exactly the diagnosis the economist John Kenneth Galbraith laid out in his 1955 study of the period, The Great Crash, 1929. Galbraith named what he called the bad distribution of income as one of the underlying weaknesses of the economy on the eve of the collapse. His point was blunt. With so much income concentrated at the top, the economy leaned heavily on the spending and investment decisions of the wealthy — which are far more volatile than the steady, grinding spending of ordinary households on rent and food and shoes. A working family spends almost everything it earns, by necessity. A rich family can suddenly stop. And an economy that depends on the rich choosing to spend is an economy with a long way to fall the moment they get nervous.
Now, you should know this is a contested reading, because honest history names its arguments. The view that underconsumption — too little buying power in ordinary hands — helped cause the Depression was central to Galbraith and the Keynesian tradition. But it's challenged hard from the monetarist side. The economists Milton Friedman and Anna Schwartz, in their landmark 1963 book A Monetary History of the United States, argued that the Depression was fundamentally a monetary catastrophe — a collapse in the money supply that the Federal Reserve failed to stop — and not principally a failure of consumer demand. In their telling, inequality wasn't the engine; bad central banking was. That debate runs through the rest of this course, and the monetarist case is genuinely powerful — you'll hear it in full when this story reaches the banks and the Fed.
But here's the thing you don't have to choose between. Inequality didn't have to be the sole cause of the Depression to be a real source of its fragility. A structure can be weak in more than one way at once. And the inequality of the twenties made the economy brittle in a specific, traceable way — which brings us back to the part of this story that's already been laid down.
Because here is where two threads of this course snap together. The earlier part of this story showed how installment credit — buy now, pay later — spread through American households in the twenties, how families bought cars and furniture and washing machines on borrowed money. Now lay that next to what you just heard about wages. If wages had been keeping pace with productivity, ordinary families could have bought all those goods outright, out of rising income. They couldn't. So how did the mass consumption happen at all, with wages this flat?
It happened on credit. That's the connection. Consumer debt and wage stagnation were not two separate facts about the 1920s — they were the same fact, seen from two sides. The reason households leaned so hard on installment borrowing is that their incomes weren't rising fast enough to buy the flood of goods the factories were producing. Credit filled the gap that wages left open. The economy kept the consumption going by lending people their own future purchasing power.
So if someone stopped you right here and asked why that's dangerous — what would you say? … Borrowed demand isn't real demand. It's demand pulled forward from tomorrow. A family buying a car on installments this year is a family that has already committed next year's income. The spending looks robust today precisely because it's been borrowed from the future. And the moment incomes wobble — the moment a paycheck shrinks or vanishes — that borrowed demand doesn't just slow down. It reverses. The payments still come due, but the income to make them is gone.
That's the vulnerability hiding under the prosperity, stated plainly: a boom propped up by borrowing from people whose wages couldn't support the borrowing in the first place. It works beautifully as long as incomes hold and confidence stays high. It fails catastrophically the instant either one breaks.
Strip away the detail and a few things are doing the real work here. Productivity raced ahead while most wages crawled. The gains piled up at the very top, leaving the broad consumer base too thin to absorb everything the economy could now produce. And the gap between what people earned and what they were expected to buy got papered over with debt — which meant the prosperity was real but rented, not owned.
And there was one group of Americans for whom this fragility wasn't a future risk at all. They were already living the collapse, a full decade before the crash — out on the land, where the boom had already gone bust.