More Math: “Why Wall Street Can’t Count”


Click on the chart for a larger version.

Cringely:

Take a look at this chart that someone sent to me a couple days ago. I’m making it big so you can see as much detail as possible. Have a look and then come back, okay?
Pretty scary, eh? It’s a chart showing the deterioration of major bank market caps since 2007. Prepared by someone at JP Morgan based on data from Bloomberg, this chart flashed across Wall Street and the financial world a few days ago, filling thousands of e-mail in boxes. Putting a face on the current banking crisis it really brought home to many people on Wall Street the critical position the financial industry finds itself in.
Too bad the chart is wrong.
It’s a simple error, really. The bubbles are two-dimensional so they imply that the way to see change is by comparing AREAS of the bubbles. But if you look at the numbers themselves you can see that’s not the case.