According to this study, money can buy happiness.  That is to say, increasing income reduces stress and increases opportunities.  Satisfaction with life increases.

I believe that money should be measured in what it can do for you and the freedom it allows in your life.  I once met a woman who won an $18 million dollar lottery several years earlier.  She paid off her parents home, bought her brother a new truck and took a very nice vacation with her husband.  After that vacation, she went back to work.  Otherwise her  life didn’t change.  She didn’t move into a fancy house.  She didn’t quit her job.  She didn’t lavish everyone wish expensive gifts.  She DID decide to stop putting in extra hours on the weekend to strive for that promotion.  She did stop worrying about unforeseen events putting her in financial distress.  It wasn’t the money that made her happier.  It was the freedom and reduction of stress that made her happier.  Had she chosen to spend her money on things, the money would have quickly made her miserable.

I just read that the lottery is $800 million tonight.  There is a fair chance that no one will win and next week’s lottery would be well over a billion dollars.  In other words, it is enough to personally pay to fly a mission to mars.  The person who win’s that will be very excited and happy initially.  Whether they choose to spend the money trying to buy happiness or whether they choose to simply have the money provide them freedom will decide how happy that money will make them in the long term.

Source: Money can buy happiness, but only to a point