The original evidence for the paradox was United States data. Subsequently, supporting findings were given for other developed nations,[2] and, more recently for less developed countries and countries transitioning from socialism to capitalism.[3] The original conclusion for the United States was based on data from 1946 to 1970; later evidence through 2014 confirmed the initial finding—the trend in United States happiness has been flat or even slightly negative over a roughly seven decades stretch in which real incomes more than tripled.