90% drop in book sales in China.

I read the headline in passing, not knowing I was going to write this, so it may be it's just the province in China. Still it's a timely reminder of what could happen.

There have been several instances of gigantic sales drops over the last 40 years. Some are systemic, such as the collapses of bubbles or steep recessions.

But some occur because of Black Swan events. The one that Linda and I both remember is the invasion of Kuwait. For some reason, this one had outsized effects. No business for weeks. It more or less was the final coffin to our Sisters store.

9/11 didn't have as big effect. I hate to credit him, but Bush's call for people to keep spending must have helped.

Anyway, there is always a chance of something like this happening, and if you don't have reserves, it can do you in.

Just another reason not to get overextended.