The Largest Killer in the Last Century

I'll give you a hint, it isn't war. 

http://www.hawaii.edu/powerkills/WSJ.ART.HTM

Capitalism works well and even repairs itself. It's surefire economical system and has no flaws, but one. The fact that under capitalism lucky corporations have ability to grow and grow until they have monopoly of market. That problem is very hard to fix too, but even with that problem capitalism beats socialism hands down.