Penalty system for motivation in combating procrastination

Implementing a penalty system to tackle procrastination can be quite effective, particularly for those of us more motivated by avoiding losses than by gaining rewards. For example, a friend of mine practices this: she has a box for money where she deposits each time she misses a deadline. I personally believe that there should be a balance between rewards and penalties, as penalties seem like very short-term motivation to me. P.S. I was sure that I was against this when reading your question, but while writing this post, I came to realize that sometimes I say, "I won't go to the restaurant before I finish this project." Yet, I believe it depends on the perspective you take: "I won't go to the restaurant before I finish this project" - penalties "I will go to the restaurant when I finish this project" - rewards