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Heterogeneity is ubiquitous in firm-level and sectoral data. Equilibrium models, how-ever, typically assume a representative firm, as in Andrew B. Abel and Olivier J. Blanchard (1983). The representative firm paradigm leaves no role for the distribution of capital. We model capital reallocation in a general equilibrium model with two sectors. Capital adjustment costs capture illiquidity in our model, similar to Hirofumi Uzawa’s (1969) capital installation technology. We follow Fumio Hayashi (1982) in assuming that the production technology is linearly homogeneous, which allows us to focus on the sectoral distribution of capital, separately from the level of total capital. The two sectors may have different levels of productivity, and we show that the distribution of capital between the two sectors is the single state variable gov-erning investment, growth, and valuation in the economy.We analytically characterize prices and quan-tities, including investment, growth, the interest rate, and the price of capital (Tobin’s

�Inattentive agents update their information sporadically, and thus respond belatedly to news. We generate optimally inattentive behavior by assuming that to observe the value of his investment portfolio the consumer must pay a cost that is proportional to the portfolio’s contempo raneous value. It is optimal for the consumer to check his investment portfolio at equally spaced points in time, consuming from a riskless trans actions account in the interim. The riskless transactions account that finances consump tion guarantees that funds are never unwittingly exhausted. � We show that the optimal interval of time between consecutive observations of the value of the portfolio is the unique positive solution to a nonlinear equation. Quantitatively, even a small observation cost (one basis point of wealth) implies a substantial (eight-month) decision interval under conventional parameter values.

This paper extends the theory of investment under uncertainty to incorporate fixed costs of investment, a wedge between the purchase price and sale price of capital, and potential irreversibility of investment. In this extended framework, investment is a non-decreasing function of q, the shadow price of installed capital. There are potentially three investment regimes, which depend on the value of q relative to two critical values. For values of q above the upper critical value, investment is positive and is an increasing function of q, as is standard in the theory branch of the adjustment cost literature. For intermediate values of q, between two critical values, investment is zero. Although this regime features prominently in the irreversibility literature, it is largely ignored in the adjustment cost literature. Finally, if q is below the lower critical value, gross investment is negative, a possibility that is ruled out by assumption in the irreversibility of literature. In general, however, the shadow price q is not directly observable, so we present two examples relating q to observable varieties.