Joseph Stiglitz discusses American inequality. He argues in an article on Evonomics:

American inequality didn’t just happen. It was created. Market forces played a role, but it was not market forces alone. In a sense, that should be obvious: economic laws are universal, but our growing inequality— especially the amounts seized by the upper 1 percent—is a distinctly American “achievement.” That outsize inequality is not predestined offers reason for hope, but in reality it is likely to get worse. The forces that have been at play in creating these outcomes are self-reinforcing.

He however makes a much wider point on the interactions between markets and government, and its impact on inequality. He writes:

Our political system has increasingly been working in ways that increase the inequality of outcomes and reduce equality of opportunity. This should not come as a surprise: we have a political system that gives inordinate power to those at the top, and they have used that power not only to limit the extent of redistribution but also to shape the rules of the game in their favor, and to extract from the public what can only be called large “gifts.” Economists have a name for these activities: they call them rent seeking, getting income not as a reward to creating wealth but by grabbing a larger share of the wealth that would otherwise have been produced without their effort. Those at the top have learned how to suck out money from the rest in ways that the rest are hardly aware of—that is their true innovation.

This approach of linking politics, markets, government – broadly a political economy approach – holds great promise for better analysis and more especially for far reaching change.