Paul Ford’s Carrot Centralization is a great plea for the importance of user research, but I think he also inadvertently came up with an excellent definition for product management:

You might think our job is to build software but just as often it’s to help you avoid building the wrong software. And when you build, build carrots.

Because, as he says earlier in the post:

Carrots work. Sticks don’t. Computers can’t make people do things. They have to want to do things.