University of Michigan world values site says that across many cultures virtually no gain in happine
University of Michigan world values site says that across many cultures virtually no gain in happiness measures above 13k annual income in 1995 dollars (i.e. getting up to basic-needs-met level does contribute to happiness but above that the correlation stops) Also notes correlation between democratic institutions and happiness. (also says genetic factors are big ones within cultures)
Source: University of Michigan world values site