Money by itself cannot generate happiness. A lot of research has been done on this topic, and the results are unwavering - money does not and can not buy happiness. In fact, happiness is not for sale. It must be earned.
According to the article above capitalism can be responsible for fostering happiness. The basic premise - if people are allowed the freedom to succeed on their own merits, then they are in the best potential environment to find, or earn, happiness. Therefore, capitalism is a critical element to the overall happiness of our society.
Please take a look at this article when you get a chance. It provides a fascinating perspective.