![Planet Money show](https://d3dthqtvwic6y7.cloudfront.net/podcast-covers/000/026/080/small/npr-planet-money.jpg)
Summary: First, an NYU finance professor talks about yesterday's wild market swings. Turns out, a sort of "circuit breaker" that's supposed to settle the market may have backfired. Then, we go behind the scenes at Standard & Poor's to answer a question that's been on our mind lately: How do you rate a country? Also answered in the podcast: Do agencies think twice before lowering a country's rating to junk?