Peter Turchin (Secular Cycles) presents a history of inequality:
From 1800 to the 1920s, inequality increased more than a hundredfold. Then came the reversal: from the 1920s to 1980, it shrank back to levels not seen since the mid-19th century. Over that time, the top fortunes hardly grew (from one to two billion dollars; a decline in real terms). Yet the wealth of a typical family increased by a multiple of 40. From 1980 to the present, the wealth gap has been on another steep, if erratic, rise. Commentators have called the period from 1920s to 1970s the ‘great compression’. The past 30 years are known as the ‘great divergence’. Bring the 19th century into the picture, however, and one sees not isolated movements so much as a rhythm. In other words, when looked at over a long period, the development of wealth inequality in the US appears to be cyclical. And if it’s cyclical, we can predict what happens next.
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First, we need to think about jobs. Unless other forces intervene, an overabundance of labour will tend to drive down its price, which naturally means that workers and their families have less to live on. One of the most important forces affecting the labour supply in the US has been immigration, and it turns out that immigration, as measured by the proportion of the population who were born abroad, has changed in a cyclical manner just like inequality. In fact, the periods of high immigration coincided with the periods of stagnating wages. The Great Compression, meanwhile, unfolded under a low-immigration regime. This tallies with work by the Harvard economist George Borjas, who argues that immigration plays an important role in depressing wages, especially for those unskilled workers who compete most directly with new arrivals.
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This connection between the oversupply of labour and plummeting living standards for the poor is one of the more robust generalisations in history. Consider the case of medieval England. The population of England doubled between 1150 and 1300. There was little possibility of overseas emigration, so the ‘surplus’ peasants flocked to the cities, causing the population of London to balloon from 20,000 to 80,000. Too many hungry mouths and too many idle hands resulted in a fourfold increase in food prices and a halving of real wages. Then, when a series of horrible epidemics, starting with the Black Death of 1348, carried away more than half of the population, the same dynamic ran in reverse. The catastrophe, paradoxically, introduced a Golden Age for common people. Real wages tripled and living standards went up, both quantitatively and qualitatively. Common people relied less on bread, gorging themselves instead on meat, fish, and dairy products.
Much the same pattern can be seen during the secular cycle of the Roman Principate. The population of the Roman Empire grew rapidly during the first two centuries up to 165AD. Then came a series of deadly epidemics, known as the Antonine Plague. In Roman Egypt, for which we have contemporary data thanks to preserved papyri, real wages first fell (when the population increased) and then regained ground (when the population collapsed). We also know that many grain fields were converted to orchards and vineyards following the plagues. The implication is that the standard of life for common people improved — they ate less bread, more fruit, and drank wine. The gap between common people and the elites shrank.
Naturally, the conditions affecting the labour supply were different in the second half of the 20th century in the US. An important new element was globalisation, which allows corporations to move jobs to poorer countries (with that ‘giant sucking sound’, as Ross Perot put it during his 1992 presidential campaign). But none of this alters the fact that an oversupply of labour tends to depress wages for the poorer section of the population. And just as in Roman Egypt, the poor in the US today eat more energy-dense foods — bread, pasta, and potatoes — while the wealthy eat more fruit and drink wine.
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Too many elites relative to the general population (a condition I call ‘elite overproduction’) leads to ever-stiffer rivalry in the upper echelons. And then you get trouble.
In the US, there is famously a close connection between wealth and power. Many well-off individuals — typically not the founders of great fortunes but their children and grandchildren — choose to enter politics (Mitt Romney is a convenient example, though the Kennedy clan also comes to mind). Yet the number of political offices is fixed: there are only so many senators and representatives at the federal and state levels, and only one US president. As the ranks of the wealthy swell, so too do the numbers of wealthy aspirants for the finite supply of political positions.
When watching political battles in today’s Senate, it is hard not to think about their parallels in Republican Rome. The population of Italy roughly doubled during the second century BC, while the number of aristocrats increased even more. Again, the supply of political offices was fixed — there were 300 places in the senate and membership was for life. By the end of the century, competition for influence had turned ugly. During the Gracchan period (139—110BC), political feuding led to the slaughter of the tribunes Tiberius and Gaius on the streets of Rome. During the next century, intra-elite conflict spilt out of Rome into Italy and then into the broader Mediterranean. The civil wars of the first century BC, fuelled by a surplus of politically ambitious aristocrats, ultimately caused the fall of the Republic and the establishment of the Empire.
Beside sheer numbers, there is a further, subtler factor that aggravates internal class rivalry. So far I have been talking about the elites as if they are all the same. But they aren’t: the differences within the wealthiest one per cent are almost as stark as the difference between the top one per cent and the remaining 99. The millionaires want to reach the level of decamillionaires, who strive to match the centimillionaires, who are trying to keep up with billionaires. The result is very intense status rivalry, expressed through conspicuous consumption. Towards the end of the Republic, Roman aristocrats competed by exhibiting works of art and massive silver decorations in their homes. They threw extravagant banquets with peacocks from Samos, oysters from Lake Lucrino and snails from Africa, all imported at great expense. Archaeology confirms a genuine and dramatic shift towards luxury.
Intra-elite competition also seems to affect the social mood. Norms of competition and extreme individualism become prevalent and norms of co-operation and collective action recede.
You should read the whole thing.