Market crash, yeah forgot to tell you guys

[oats]

This is the one-liner you need to know: it allows anyone to participate in the economy, at virtually all levels. It gives corporations someone to answer to, the shareholders.

If you're genuinely interested, read Finance and the Good Society by Robert Shiller. Talks a good bit about the history of stock markets (and other markets), why they're important, how they help, and ultimately how they should behave in a "good society."