Aside from the allegations of sexism, Larry Summers and Russell Brand don't seem to have much in common. But they do. Summers' talk of secular stagnation corroborates the idea that politicians are out of touch not just with voters but with reality.
The thing is, there is nothing much new in what Summers says. Ben Bernanke's famous "investment dearth" speech was made eight years ago, and UK firms' capital spending has been lagging behind retained profits for over a decade. The lack of investment which lies behind sluggish growth is an old problem.
But it's one our political class barely discusses. Tories seem unaware that the stagnation of the pre-recession years refutes the notion that lowish taxes and a quiescent workforce are sufficient to boost investment. And Labour and - more bizarrely still some of the broader left - seem to think austerity is the cause of our problems rather than an exacerbating symptom of them. The question: "what if trend growth is very low?" doesn't seem to be on the agenda.
What if it were? The answers, I suspect, would fall into two sorts.
One would be to pay more attention to ways of increasing trend growth. These might include supply-side socialism, a greater socialization of investment and perhaps bigger government. They would also include - as Duncan stresses - policies which ensure that companies are run for the long-term, rather than in the short-term interests of rent-seekers.
However, the fact that national long-run growth rates have not been greatly affected by government policies in the past warns us that such measures might not be enough.
Which leads to the second set of questions: if we are stuck in low trend growth, how can we minimize the pain of this? Questions of how to achieve efficient redistribution, and how to pool economic risks thus become more important. Basic income, anyone?
But the mere raising of these issues only shows that there's a massive gulf between the petty preoccupations of the political class (which includes the mainstream media) on the one hand, and the scale of our economic problems on the other.
For a long time, mainstream party politics has assumed that the private sector will deliver decent long-run economic growth if only it can get the right conditions. The possibility that this assumption is wrong is one the political elite doesn't seem much interested in. As Mr Brand said, the political system is apathetic to the needs of the people.