[triceratops]

> does passages like "I've always thought that under-populated countries in Africa are vastly UNDER-polluted, their air quality is probably vastly inefficiently low compared to Los Angeles or Mexico City" seem a joke?

> what is the punchline?

It's akin to saying "This establishment's high Google/Yelp ratings indicate it's leaving money on the table. There's clearly room to raise prices, cut costs, and really degrade the customer experience."

I don't know if Summers is telling the truth about his intent. But as far as jokes go, it's decent.