Scalpers provide liquidity to producers of goods in markets that don't need additional liquidity. For the consumers, he does not provide any liquidity at all. So effectively, scalpers do not provide any "effective" liquidity.
Scalpers always buy stuff where there is already high organic demand from actual end users, because scalping only works if demand outstrips supply. This demand is the liquidity the producer of the stuff needs, and it's already sufficient for them to sell all their inventory quickly, so the scalper obviously does not provide any useful service to the producer.
For the buyers, they act as a seller, but for each item they offer, the original producer has one less to offer, as the scalper has bought it from the original producer. Therefore, they provide exactly no additional liquidity for the end user.
The only thing they do is ratchet up prices and reduce customer service levels (the original producer or an actual, professional reseller will most likely offer better customer services than some random guy on eBay), which are both net negatives for everyone but the scalper.
Aha, I was thinking of scalpers like the guy outside the stadium buying and selling tickets from fans, creating a secondary market. I can see how a scalper who swoops in and buys up the original tickets is not doing that.
Scalpers always buy stuff where there is already high organic demand from actual end users, because scalping only works if demand outstrips supply. This demand is the liquidity the producer of the stuff needs, and it's already sufficient for them to sell all their inventory quickly, so the scalper obviously does not provide any useful service to the producer.
For the buyers, they act as a seller, but for each item they offer, the original producer has one less to offer, as the scalper has bought it from the original producer. Therefore, they provide exactly no additional liquidity for the end user.
The only thing they do is ratchet up prices and reduce customer service levels (the original producer or an actual, professional reseller will most likely offer better customer services than some random guy on eBay), which are both net negatives for everyone but the scalper.