This study reviews the empirical literature on the integration properties of energy consumption and production. The survey begins with a discussion of the implications of whether energy variables contain a unit root and proceeds to examine how results differ according to the specific unit root...

In many countries, the GDP share of the public sector increases with per capita income but happiness fails to register a long-term upward trend. Most objective indicators of the quality of life also do not correlate positively with income but improve with time associated with the advancement of...