This is the kicker - and the rarity. I don't think it's all trust, though. When your boss already knows going into Q1 that he's going to be fired in Q2 if he doesn't get 10 specific (and myopically short-term) agenda items addressed, it doesn't matter how much he trusts you, you're going to be focusing on only the things that have the appearance of ROI after a few hours of work, no matter how inefficient they are in the long term.
This is the kicker - and the rarity. I don't think it's all trust, though. When your boss already knows going into Q1 that he's going to be fired in Q2 if he doesn't get 10 specific (and myopically short-term) agenda items addressed, it doesn't matter how much he trusts you, you're going to be focusing on only the things that have the appearance of ROI after a few hours of work, no matter how inefficient they are in the long term.