Thomas Piketty's impressive and much-discussed book Capital in the Twenty-First Century has brought considerable attention to the problem of rising economic inequality. But it is not strong on solutions. As Piketty admits, his proposal — a progressive global tax on capital (or wealth) – "would require a very high and no doubt unrealistic level of international cooperation."
We should not be focusing on quick solutions. The really important concern for policymakers everywhere is to prevent disasters — that is, the outlier events that matter the most. And, because inequality tends to change slowly, any disaster probably lies decades in the future.
That disaster — a return to levels of inequality not seen since the late nineteenth to early twentieth century — is amply described in Piketty's book. In this scenario, a tiny minority becomes super-rich — not, for the most part, because they are smarter or work harder than everyone else, but because fundamental economic forces capriciously redistribute incomes.