I find the general message more interesting than increase and decrease of happiness from exact amount A to B.
No one is arguing that money can't make life better. Of course it can! But part of what this article says is that it's *how* you use your money, and your expectations of that money and what it can buy, that make you happy.
Oddly, what the article doesn't explore is what people *sacrifice* in order to go up in salary. I actually did the dip recently, and went down in salary - but I went way up in time. Am I happier? Oh, yes I am. Earning more money does not come cheaply, to coin a phrase, and frankly the extra stuff I could buy then can NEVER make up for the life I sacrificed to make the money to buy it.
Of course, I didn't buy a laundress. Maybe that was my mistake. Next time.