The literature on the aggregation of (S, s) policies has ignored the impact of aggregate behavior on the individual's optimization problem. In the case of pricing, the feedback effects are clear. Not only do pricing strategies determine the evolution of the price level, but the evolution of the price level also influences the optimal pricing strategies. In this paper, we provide a consistent treatment of aggregation and optimization. We use this model to analyze three issues in the menu cost pricing literature: the relationship between strategic complementarity and the real effects of money; the relationship between the variance of the money supply and the correlation between money and output; and the relationship between the cost of price adjustment and the size of price adjustment. QUESTIONS CONCERNING THE DYNAMICS of aggregate variables such as prices, employment, investment, and consumption represent the core of business cycle analysis. One striking feature of these variables is the radical difference between properties of these aggregates and the nature of the individual behavior that underlies them. The behavior of a firm's prices, investment and employment, and the behavior of an individual's consumption all involve frictional elements that lead to discrete adjustment at the microeconomic level. Heterogeneity among individuals, however, tends to smooth the behavior of the corresponding aggregates. In recent years, a large body of research has developed to examine the manner in which microeconomic frictions influence aggregate dynamics. One of the centerpieces of this research has been the (S, s) model developed by Arrow, Harris, and Marschak (1951). The key element of this model is the state dependence of individual decisions. Agents act when a state variable crosses some critical threshold which balances the cost and benefits of adjustment. The aggregate implications of this form of microeconomic behavior have been analyzed by Blinder (1981), Caplin (1985), and Mosser (1991) in the context of inventory dynamics; by Caplin and Spulber (1987), Caballero and Engel (1991, 1993), and Caplin and Leahy (1991) in the context of prices; and by Bertola and Caballero (1990), Caballero (1993), and Eberly (1994) in the context of con- sumer durables. One of the most limiting aspects of these models is that they focus exclusively on the impact that microeconomic inertia has on aggregate dynamics. They 1We would like to thank Michael Harrison, loannis Karatzas, John Leahy Sr., Andreu Mas-Colell, a co-editor and four anonymous referees for helpful discussions and comments, and the National Science Foundation and the Sloan Foundation for financial support.

The authors present a three-stage model of market dynamics. In the first stage, routine behavior tends to keep information of common interest trapped in private hands. In the second stage, private information reaches a threshold that triggers some agents to alter their behavior; these actions release information to the market. The final stage involves the market's response to this news as other participants react to the initial departure from routine behavior. The authors present an application to industry investment. They also outline applications to the international debt crisis, to bank runs, and to political upheavals.

We develop an analytically tractable Phillips curve based on state‐dependent pricing. We consider a local approximation around a zero inflation steady state and introduce infrequent idiosyncratic shocks. The resulting Phillips curve is a simple variant of the conventional time‐dependent Calvo formulation with important differences. First, the model is able to match the micro evidence on the magnitude and timing of price adjustments. Second, our state‐dependent model exhibits greater flexibility in the aggregate price level than the time‐dependent model. With real rigidities present, however, our model can exhibit nominal stickiness similar to a conventional time‐dependent model.

We study the cyclical effects of the timing of durable goods purchases in a general equilibrium model in which both durable and non-durable goods are consumed and the durable good is lumpy, At the microeconomic level, the timing of durable goods purchases supplies some insulation for nondurable consumption over the cycle. At the macroeconomic level, the timing decisions tend to amplify and propagate wealth and income shocks. Our model also allows for endogenous price determination. When the price of the durable changes due to inflexibility of workers between sectors, the effect of adverse shocks is even stronger and longer.

We present a model of the market for a used durable in which agents face fixed costs of adjustment, the magnitude of which depends on the degree of adverse selection in the secondary market. We find that, unlike typical models, the sS bands in our model contract as the variance of the shock increases. We also analyze a dynamic version of the model in which agents are allowed to make decisions that are conditional on the age of the durable. We find that, as the durable ages, the lemons problem tends to decline in importance, and the sS bands contract.

We unite two basic approaches to modelling limited attention in choice by showing that the rational inattention model implies the formation of consideration sets—only a subset of the available alternatives will be considered for choice. We provide necessary and sufficient conditions for rationally inattentive behaviour which allow the identification of consideration sets. In simple settings, chosen options are those that are best on a stand-alone basis. In richer settings, the consideration set can only be identified holistically. In addition to payoffs, prior beliefs impact consideration sets. Linear inequalities identify all priors consistent with each possible consideration set.

We introduce a simple method of recovering attention costs from choice data. Our method rests on a precise analogy with production theory. Costs of attention determine consumer demand and consumer welfare, just as a competitive firm’s technology determines its supply curve and profits. We implement our recovery method experimentally, outline applications, and link our work to the broader literature on inattention and mistaken decisions.

The (S, s) model has enjoyed tremendous popularity over the past decade. It has been employed almost everywhere that discrete adjustment is observed. Today microeconomic rigidities are seen as an important influence on aggregate dynamics. In this paper we quickly characterize the microeconomic evidence for the model. To narrow the scope of our discussion, we will focus our attention on real variables, and we will comment on price inertia where appropriate. We conclude that, in spite of its popularity, the evidence for the importance of the (S, s) adjustment is surprisingly weak. We argue that discrete adjustment is, in and of itself, of little macroeconomic interest. To be important these frictions must coordinate agents to act together, thereby exacerbating deviations from the neoclassical benchmark. To date there have been few attempts at empirically identifying such interactions. In the last section, we present some results of our own. We test one of the main implications of (S, s) adjustment, that a greater variance in the forcing process leads to more frequent adjustment. Using data on automobiles from the Consumer Expenditure Survey, we find that more variable income leads to less frequent adjustment. We speculate that this correlation is indicative of a link between discrete adjustment and imperfect capital markets. This interaction could provide an important role for (S, s) frictions.

We introduce three new classes of attention cost functions: posterior separable, uniformly posterior separable, and invariant posterior separable. As with the Shannon cost function, all can be solved using Lagrangian methods. Uniformly posterior-separable cost functions capture many forms of sequential learning and hence play a key role in many applications. Invariant posterior-separable cost functions make learning strategies depend exclusively on payoff uncertainty. We introduce two behavioral axioms, Locally Invariant Posteriors and Only Payoffs Matter, which identify posterior-separable functions as uniformly and invariant posterior separable, respectively. In combination, they pinpoint the Shannon cost function.

We develop a survey instrument to measure self-control problems in a sample of highly educated adults. This measure relates in the manner that theory predicts to liquid wealth accumulation and personality measures. Yet while self-control problems are typically seen as resulting in overconsumption and low wealth, we identify a significant group who underconsume and thereby accumulate high levels of wealth. In addition, self-control problems are smaller in scale for older than for younger respondents. Those who put money aside in retirement accounts may be delaying access to a point at which self-control problems are no longer important.