In their book Happy Money: The Science of Smarter Spendingauthors Elizabeth Dunn and Michael Norton draw on years of quantitative and happt research to explain how money can buy happiness, but only if we spend it in certain ways. The key lies in adhering to five key principles: Buy Experiences research shows that material purchases are less sprnding than vacations or concerts ; Make it a Treat limiting access to our favorite things will make us keep appreciating them ; Buy Time focusing on time over money yields wiser purchases ; Pay Now, Consume Later delayed consumption leads to increased enjoyment ; and Invest in Others spending money on other people makes us happier than spending it on. Recently we featured a video illustrating the emotional benefits of buying experiences. In the following sequel, Norton again gives some cash to two women in Harvard Square. The catch this time: Each of them must spend the money on someone. If you have a nice car and a big house on an island by your...