This is not to link between income and satisfaction hs dee snappad .Poor countries still lag behind : oniy a quuarter of the people there are in the happy tiers - half the ievel of the other two groups . There is also a clear link detween happiness and income growth ( as opposed to income levels ) . China' s GDP rose at annual average rate of 10 % in 2007 - 14 and its happiness level rose 26 points.