The approach explored in this book poses a challenge to various notions of conducting economic research. First, the concept of rationality that is commonly used in economics is examined. Researchers who take it for granted that a theory of rational expectations should start from a normative standpoint find their assumption questioned. The work presented here documents a theory of bottom-up rationality. A second group of scholars find their beliefs questioned. The testing of hypotheses is not the only task to be addressed in the controlled environment of a laboratory. Instead, the economics laboratory can be fruitfully used for quantifying behavioral models. Such bottom-up models can serve as a basis for many forms of applied empirical work.