Market drop: Thinking man’s rout

The S&P 500 index of US stocks fell another 6% on Wednesday. That isn’t exactly good news, but at least there are welcome signs of rationality in the latest rout. Investors appear more motivated by fundamental trends than indiscriminate fear. Right now, clearer thinking still leads to lower share prices. Government actions around the globe have begun to thaw credit concerns, but the quarterly earnings season in the US and Europe is making clear that the economy is weakening, drawing profit pros...