1. No one assumes that they have perfect information. No one says this is perfect just better than the other ways to handle these situations!

2. Who do you think will consistently have better information than someone whose sole goal is to sell these tickets?

3. If they are consistently losing money scalping and not selling tickets they won't be a scalper much longer.

4. This is a dynamic process which can account for changing variables regarding supply and demand quickly as opposed to rules and regulations which do not.

5. If they only sell half the tickets at 4x then they could sell the last half at an extreme discount and make even more than double their investment! Do you think they would rather make more money or less?

For 5. consider the diamond industry as a real world example of an industry well renowned for aggressively limiting supply.

Scarcity can drive price upwards in an exponential way that ends up making it optimal to not sell all inventory. Sure in an ideal world you would sell everything you can for the maximum price but in the real world the buyer is incentivized to wait until you offer your minimal price.

> It’s perfectly rational for a scalper to regularly purchase more tickets than they sell due to the kind of markup their looking for. At say 4x they could on average sell 1/2 the tickets while doubling their investment.

True, but in that case they've added more value than they've subtracted. That artists insist on pricing every concert to sell out is a big part of the problem here; you'd get a more functional market by accepting a few empty seats to give some slack.

Bands want to present the appearance of a successful band, it helps their image. A filled stadium is part of that, so yes they can make more money today by raising prices but that’s making real trade offs.