The inherently chaotic, crisis-prone nature of capitalism was a key part of Marx's writings. He argued that the relentless drive for profits would lead companies to mechanize their workplaces, producing more and more goods while squeezing workers' wages until they could no longer purchase the products they created. Sure enough, modern historical events from the Great Depression to the dot-com bubble can be traced back to what Marx termed "fictitious capital" – financial instruments like stocks and credit-default swaps. We produce and produce until there is simply no one left to purchase our goods, no new markets, no new debts. The cycle is still playing out before our eyes: Broadly speaking, it is what made the housing market crash in 2008. Decades of deepening inequality reduced incomes, which led more and more people to take on debt. When there were no sub-prime borrows left to scheme, the whole facade fell apart, just as Marx knew it would.