According to Veenhoven’s work, there have been increases in average levels of reported happiness over time. In wealthy countries, these changes have been slight, but in less developed countries, the changes have been pronounced. In the United States, however, there has been essentially no change in the reported levels of happiness over the past sixty years. These findings have been used by Richard Easterlin to support a theory that living conditions, which have risen steadily in the United States over the past sixty years, do not affect happiness. If we consider the findings on both developed and less-developed countries, we can see that happiness is most strongly related to living conditions when money is scarce and living conditions are less than optimal. After people reach a reasonable standard of living, however, affluence does not add much to happiness.