Chapter 10. Levels of Reasoning in Keynesian Beauty Contests: A Generative Framework We introduce a generalization of the Beauty Contest (BC) game as a framework that incorporates different models from micro and macroeconomics by formulating their reduced forms as special cases of the BC. Examples include public good games ultimatum games Bertrand Cournot some auctions asset markets New Keynesian and general equilibrium models with sentiments animal spirits. This becomes feasible by considering BC specifications with a best response or optimal action as a function of other players aggregated actions. For characterizing an integrated account of heterogeneity in economics as observed in BC experiments we employ a non equilibrium model the so called “level k” model based on one (or more) reference point(s) and (limited) iterated best responses. Level k and related models thus bridge the gap between non strategic (e.g. irrational intuitive or random) behavior and equilibrium choices. We also give a brief overview of interactive decision making within experimental economics and discuss elicitation methods cognitive and population measures to better understand heterogeneity in human reasoning in general and in economic experiments in particular.