This thesis is structured around two main chapters which study the role of individuals' beliefs in affecting the asset markets and the macroeconomy. The first chapter of my thesis is based on a joint work with Paul Ehling and Christian Heyerdahl-Larsen in which we study asset prices and portfolio choice when agents learn from their own experience. We develop a general equilibrium overlapping generations economy with learning in which cohort specific experience drives beliefs about consumption growth and through that affects equilibrium outcomes. The main findings are that the young act as trend chasers, wealth shifts from young to old, the market price of risk is countercyclical and the risk free rate of return is pro-cyclical. Importantly,...