PORTFOLIO CHOICES,CONSUMPTION, AND PRICES IN A MARKET WITH DURABLE ASSETS

Recent research in investments has focused almost exclusively on financial assets such as corporate stocks. Although durable assets constitute an important part of investors' holdings, little effort has been made to explore their role in individuals' investments decisions and on assets pricing. This paper establishes results concerning the role of durable assets in the determination of optimum portfolio choices. The paper explores the effect of consumption considerations related to the service flows generated by durable assets on optimum portfolio considerations and asset prices. The main result is tied to the existence, or lack thereof, of efficient rental markets. In the absence of rental markets (or with restrictions on renting), investors' portfolio choices are not independent of consumption considerations as they are assumed to be in the standard CAPM. Individuals may thus hold different portfolios, and prices reflect the owner's inability to trade consumption flows. Under perfect market assumptions with unrestricted rental markets, optimum portfolio choices are undistinguishable from those implied by the standard CAPM in the sense that they are mean-variance efficient and identical for all individuals. Consumption is adjusted by trading service flows in the rental market. Prices, and the price of risk, however, reflect the existence of durable assets service flows as well as the risks involved in trading these flows in the rental market. In the model, risky rental income is introduced by uncertain rental costs. Equilibrium rental rates, an important part of the return expected from holding durable assets, are determined in the context of the mean-variance framework as a function of return and undiversifiable risk.