Matthew Yglesias writes:

If the entire population of Bangladesh dropped dead tomorrow, [the world's] per capita GDP would go up. A 20 percent increase in the death rate of Americans over the age of 65 would cause our per capita growth rate to accelerate. It’s important to understand these facts, but it’s strange to think of them as optimistic scenarios...

I'm embarrassed how often I need to be reminded of economics' limitations.  But I'm not surprised it's Yglesias who brings me back.