The paper speaks to markets where there is strong information asymmetry, not all markets, and it doesn’t follow that no good can be traded, it simply says that

The paper speaks to markets where there is strong information asymmetry, not all markets, and it doesn’t follow that no good can be traded, it simply says that in such a market, people will hold goods they feel have actual value and trade those that don’t. Even in such a market for lemons, that doesn’t mean no lemons will be traded, it means that buyers price everything like a lemon, and we still have a functioning market. I don’t know about the whole world, but up here in Canada the used car market is exactly like this. Nobody trusts that guy with a small lot who operates out of a portable, so they won’t pay good money for anything he sells. So he has no incentive to sell good cars. I bought a used car… From a dealer, and I have a factory warranty on it. That’s a market where there is less information asymmetry: I know the dealer was required to bring the car up to a certain level of service for it to qualify for the factory warranty, and I know that if it breaks down, I can get it serviced. Cars that don’t meet this standard are sold by dealers too, but you can’t get a factory warranty, and they are priced accordingly. They might be good, but if a car meets the standard for a factory warranty, what dealer would offer it without that warranty, just to deal with customers who are skeptical of its reliability? A market for lemons is still a market, and it finds an equilibrium where the lemon-ness gets priced into transactions. People certainly can and do trade lemons.