Know the Market Cold
The good PM's authority doesn't come from a title. It comes from knowledge: the market, the product, the product line, and the competition, known extremely well. From that base they operate with confidence, and the rest of the team follows because the PM is usually right.
This is why the essay insists PMs are not marketing resources to be borrowed for a launch deck. Horowitz calls the good PM the marketing counterpart of the engineering manager. Peer to peer, not support staff.
A bad PM skips the homework and tries to run the role on process and meetings instead. Without deep market knowledge, every decision becomes a negotiation, and the PM loses every negotiation with someone who knows more.
“Good product managers know the market, the product, the product line and the competition extremely well and operate from a strong basis of knowledge and confidence.”
Key idea
A PM's real authority is earned knowledge of market, product, and competition. Without it, the title is decoration.