This appeal to reward is often overgeneralized, for most political budgets do not focus on simply one issue. Cutting taxes might be the least important issue facing the public, yet can suddenly become the number one focus of your local politician. When people know that they are going to be getting some money, they listen extra hard. These arguments are usually nothing more than carrots dangling before starry-eyed followers. More thoughtful individuals will seek to understand the other side of the argument so they can be fully aware of what they are giving up before they agree to such a proposal.
Teachers love wielding rewards and punishments, often in the form of grades.
The fact that this teacher feels obligated to offer extra credit for simply fulfilling an assignment expectation is unreasonable logically, but ironically makes psychological sense. Most students do not view submitting an assignment on time as a rewarding experience. Personally, I have always been amazed at how hard some students will work for one point of extra credit, but would place no effort at all in an assignment worth 100 points.