Debate: What Kind of Inequality Matters?

Inequality has emerged as a contentious issue since the financial crisis, and it figures prominently in the presidential campaigns of both political parties. Bloomberg View columnists Megan McArdle and Noah Smith try to make sense of it and figure out what, if anything, should be done.

Megan: What sort of inequality should we care about? Wealth inequality, income inequality, inequality of opportunity, inequality of mobility -- these tend to get lumped together. No amount of fair opportunity will produce similar outcomes for two different people. This tends to get ignored, because it's inconvenient for both sides.

So what kinds of inequality should we talk about? And what kinds should make us shrug and say, "Yeah, well, life's rough sometimes"?