Before we can begin our empirical appraisal of the effects of political outcomes on human happiness, we must first familiarize ourselves with the social scientific literature on subjective well-being. This chapter is thus devoted to developing the intellectual infrastructure needed to approach well-being in the way we study more conventional topics in the human sciences. I begin with the obvious question of measurement, considering if such a seemingly complex and multifaceted issue as happiness can be studied with survey data. As we shall see, it is now widely agreed that subjective appreciation of life can indeed be approached using such methods.

Given that we can measure subjective well-being, we are in a position to propose and to test theories about its nature and causes, using both individual- and national-level factors as our explanatory variables. I review two types of such theories, before providing the synthesis which informs the present analysis. The first suggests that happiness is largely a function of inner psychological processes, depending variously on genetic inheritance, general personality structures, adaptation to environment, or social comparison. The other suggests just the opposite by maintaining that our happiness depends in the main on the extent to which our needs as human animals are gratified. Although these approaches are sometimes sharply contrasted (see, e.g., Veenhoven, 2009), I argue that they are, for present purposes, complementary.