'Epidemiological' models of belief formation put social interactions at their core; such models are widely used by scholars who are not economists to study the dynamics of beliefs in populations. We survey the literature in which economists attempting to model the consequences of beliefs about...

"Buffer-stock" versions of the dynamic stochastic optimizing model of saving are now standard in the consumption literature. This paper builds theoretical foundations for rigorous understanding of the main characteristics of buffer stock models, including the existence of a target level of...

This paper introduces a method for solving numerical dynamic stochastic optimization problems that avoids rootfinding operations. The idea is applicable to many microeconomic and macroeconomic problems, including life cycle, buffer-stock, and stochastic growth problems. Software is provided

Since the foundational work of Keynes (1936), macroeconomists have emphasized the importance of agents' expectations in determining macroeconomic outcomes. Yet in recent decades macroeconomists have devoted almost no effort to modeling actual empirical expectations data, instead assuming all...

This paper argues that the modern stochastic consumption model, in which impatient consumers face uninsurable labor income risk, matches Milton Friedman's (1957) original description of the Permanent Income Hypothesis much better than the perfect foresight or certainty equivalent models did. The...

The budget constraint requires that, eventually, consumption must adjust fully to any permanent shock to income. Intuition suggests that, knowing this, optimizing agents will fully adjust their spending immediately upon experiencing a permanent shock. However, this paper shows that if consumers...

Papers in variety of disparate literatures have recently suggested that habit formation in consumption may explain several empirical puzzles, ranging from the level and cyclical variability of the equity premium (Abel (1990,1999); Constantinides (1990); Jermann (1998); Campbell and Cochrane...

Recent research has shown that rich' households save at much higher rates than others (see Carroll (2000); Dynan, Skinner, and Zeldes (1996); Gentry and Hubbard (1998); Huggett (1996); Quadrini (1999)). This paper documents another large difference between the rich and the rest of the...

This paper considers several alternative explanations for the fact that households with higher levels of lifetime income ( the rich') have higher lifetime saving rates (Dynan, Skinner, and Zeldes (1996); Lillard and Karoly (1997)). The paper argues that the saving behavior of the richest...

This paper shows that standard empirical methods for estimating log-linearized consumption Euler equations cannot successfully uncover structural parameters like the coefficient of relative risk aversion from the dataset of simulated consumers behaving exactly according to the standard model....