Being Chinese there are some thing in our culture that I'm ashamed of
One is of "face"
Obama wants to deal with China. China is all about face. If you make China lose face, they will do what it takes to regain it. China has the upper hand right now. How? They are the one buying up the bonds that support our deficite. They hold the cards (or don't buy it seems) also China produce and have access to produce many goods that U.S. use today.
There is no economical impact (at least not by much IMO) of Obama siding with the Dalai Lama other than a moral or spiritual one. At the end of the day, most of us would probably want to save a buck vs spending 10times more elsewhere just for moral reasons (I use "us" as a general terms, some of y'all might actually would spend more if they were 10 times more just for moral reasons)