The current financial crisis is generally blamed on feckless bankers, financial deregulation, crony capitalism and the like. While all of these elements may be true, this purely financial explanation of the crisis overlooks its fundamental reasons. They lie in the real sector, and more exactly in the distribution of income across individuals and social classes. Deregulation, by helping irresponsible behavior, just exacerbated the crisis; it did not create it.

To go to the origins of the crisis, one needs to go to rising income inequality within practically all countries in the world, and the United States in particular, over the last thirty years. In the United States, the top 1 percent of the population doubled its share in national income from around 8 percent in the mid-1970s to almost 16 percent in the early 2000s. That eerily replicated the situation that existed just prior to the crash of 1929, when the top 1 percent share reached its previous high watermark American income inequality over the last hundred years thus basically charted a gigantic U, going down from its 1929 peak all the way to the late 1970s, and then rising again for thirty years.

What did the increase mean? Such enormous wealth could not be used for consumption only. There is a limit to the number of Dom Pérignons and Armani suits one can drink or wear. And, of course, it was not reasonable either to “invest” solely in conspicuous consumption when wealth could be further increased by judicious investment. So, a huge pool of available financial capital—the product of increased income inequality—went in search of profitable opportunities into which to invest.

But the richest people and the hundreds of thousands somewhat less rich, could not invest the money themselves. They needed intermediaries, the financial sector. Overwhelmed with such an amount of funds, and short of good opportunities to invest the capital as well as enticed by large fees attending each transaction, the financial sector became more and more reckless, basically throwing money at anyone who would take it. While one cannot prove that investible resources eventually exceeded the number of safe and profitable investment opportunities (since nobody knows a priori how many and where there are good investment opportunities), this is strongly suggested by the increasing riskiness of investments that the financiers had to undertake.

But this is only one part of the equation: how and why large amounts of investable money went in a search of a return on that money. The second part of the equation explains who borrowed that money. There again we go back to the rising inequality. The increased wealth at the top was combined with an absence of real economic growth in the middle. Real median wage in the United States has been stagnant for twenty five years, despite an almost doubling of GDP per capita. About one-half of all real income gains between 1976 and 2006 accrued to the richest 5 percent of households. The new “gilded age” was understandably not very popular among the middle classes that saw their purchasing power not budge for years. Middle class income stagnation became a recurrent theme in the American political life, and an insoluble political problem for both Democrats and Republicans. Politicians obviously had an interest to make their constituents happy for otherwise they may not vote for them. Yet they could not just raise their wages. A way to make it seem that the middle class was earning more than it did was to increase its purchasing power through broader and more accessible credit. People began to live by accumulating ever rising debts on their credit cards, taking on more car debts or higher mortgages. President George W. Bush famously promised that every American family, implicitly regardless of its income, will be able to own a home. Thus was born the great American consumption binge which saw the household debt increase from 48 percent of GDP in the early 1980s to 100 percent of GDP before the crisis.

The interests of several large groups of people became closely aligned. High net-worth individuals and the financial sector were, as we have seen, keen to find new lending opportunities. Politicians were eager to “solve” the irritable problem of middle class income stagnation. The middle class and those poorer than them were happy to see their tight budget constraint removed as if by magic wand, consume all the fine things purchased by the rich, and partake in the longest US post World War II economic expansion. Suddenly, the middle class too felt like the winners.

This is what more than two centuries ago, the great French philosopher Montesquieu mocked when he described the mechanism used by the creators of paper money in France (an experiment that eventually crumbled with a thud): ‘People of Baetica”, wrote Montesquieu, “do you want to be rich? Imagine that I am very much so, and that you are very rich also; every morning tell yourself that your fortune has doubled during the night; and if you have creditors, go pay them with what you have imagined, and tell them to imagine it in their turn”.

The credit-fueled system was further helped by the ability of the US to run large current account deficits; that is, to have several percentage points of its consumption financed by foreigners. The consumption binge also took the edge off class conflict and maintained the American dream of a rising tide that lifts all the boats. But it was not sustainable. Once the middle class began defaulting on its debts, it collapsed.

We should not focus on the superficial aspects of the crisis, on the arcane of how “derivatives” work. If “derivatives” they were, they were the “derivatives” of the model of growth pursued over the last quarter a century. The root cause of the crisis is not to be found in hedge funds and bankers who simply behaved with the greed to which they are accustomed (and for which economists used to praise them). The real cause of the crisis lies in huge inequalities in income distribution which generated much larger investable funds than could be profitably employed. The political problem of insufficient economic growth of the middle class was then “solved” by opening the floodgates of the cheap credit. And the opening of the credit floodgates, to placate the middle class, was needed because in a democratic system, an excessively unequal model of development cannot coexist with political stability.

Could it have worked out differently? Yes, without thirty years of rising inequality, and with the same overall national income, income of the middle class would have been greater. People with middling incomes have many more priority needs to satisfy before they become preoccupied with the best investment opportunities for their excess money. Thus, the structure of consumption would have been different: probably more money would have been spent on home-cooked meals than on restaurants, on near-home vacations than on exotic destinations, on kids’ clothes than on designer apparel. More equitable development would have removed the need for the politicians to look around in order to find palliatives with which to assuage the anger of the middle-class constituents. In other words, there would have been more equitable and stable development which would have spared the United States, and increasingly the world, an unnecessary crisis.