We provide a price characterization of efficient contingent claims-that is, chosen by at least a rational agent-in multiperiod economies with market frictions. Frictions include market incompleteness, transaction costs, short-selling, and borrowing costs. We characterize the inefficiency cost of a trading strategy-its required investment minus the largest amount necessary to obtain the same utility level-and we propose a measure of portfolio performance. We show that arbitrage bounds cannot be tightened based on efficiency without restricting preferences or endowments. We observe common investment strategies becoming inefficient with market frictions and others rationalized by them.

If a pricing kernel assigns a premium to a risk variable that differs from the one assigned by the minimum-variance admissible kernel, then the pricing kernel must exhibit more variability than the minimum-variance kernel. Based on this intuition, the authors derive a variance bound that is more stringent than that of Lars Peter Hansen and Ravi Jagannathan (1991). When the authors apply their bound to the kernel of a representative consumer with power utility, they find that the consumption risk premium increases the severity of the 'equity-premium puzzle' of Rajnish Mehra and Edward C. Prescott (1985).

This paper tries to explain why the issuers of an asset would restrict what information is available about their asset. In a world where knowledge is valued, market forces should induce disclosure, but we often see markets (such as the market for mortgage-backed securities) where assets' issuers refuse to release valuable information. We present a model of market liquidity and find that market liquidity can both rise and fall with the quantity of released information. More information may increase asymmetries of information and “lemons” style breakdowns. We find that asset bundling is more advantageous when private information is more accurate, which may be the case in the mortgage-backed securities market.Journal of Economic LiteratureClassification Numbers: G14, G32.

In this paper we provide a price characterization of efficient consumption bundles in multiperiod economies with market frictions. Efficient consumption bundles are those that are chosen by at least one rational agent with monotonic state-independent and risk-averse preferences and a given future endowment. Frictions include dynamic market incompleteness, proportional transaction costs, short selling costs, borrowing costs, taxes, and others. We characterize the inefficiency cost of a trading strategy -the difference between the investment it requires and the largest amount required by any rational agent to obtain the same utility level - and we propose a measure of portfolio performance based on it. We also show that the arbitrage bounds on a contingent claim to consumption cannot be tightened based on efficiency arguments without restricting preferences or endowments. We examine the efficiency of common investment strategies in economies with borrowing costs due to asymmetric information, short selling costs, or bid-ask spreads. We find that market frictions generally change and typically shrink the set of efficient investment strategies, shifting investors away from well-diversified strategies into low cost ones, and for large frictions into no trading at all. Hence we observe strategies that become inefficient with market frictions, as well as strategies that are rationalized by market frictions.

If a pricing kernel assigns a premium to a risk variable that differs from the one assigned by the minimum‐variance admissible kernel, then the pricing kernel must exhibit more variability than the minimum‐variance kernel. Based on this intuition, we derive a variance bound that is more stringent than that of Hansen and Jagannathan (1991) . When we apply our bound to the kernel of a representative consumer with power utility, we find that the consumption risk premium increases the severity of the “equity‐premium puzzle” of Mehra and Prescott (1985) .

If a pricing kernel assigns a premium to a risk variable that differs from the one assigned by the minimum-variance admissible kernel, then the pricing kernel must exhibit more variability than the minimum-variance kernel. Based on this intuition, we derive a variance bound that is more stringent than that of Hansen and Jagannathan (1991). When we apply our bound to the kernel of a representative consumer with power utility, we find that the consumption risk premium increases the severity of the “equity-premium puzzle” of Mehra and Prescott (1985).

Recent theories of economic growth, including those of P. Romer (1986, 1990), M. Porter (1990), and J. Jacobs (1969, 1984), have stressed the role of technological spillovers in generating growth. Because such knowledge spillovers are particularly effective in cities, where communication between people is more extensive, data on the growth of industries in different cities allow the authors to test some of these theories. Using a new data set on the growth of large industries in 170 U.S. cities between 1956 and 1987, they find that local competition and urban variety, but not regional specialization, encourage employment growth in industries. The evidence suggests that important knowledge spillovers might occur between rather than within industries.

Recent theories of economic growth, including those of Romer, Porter, and Jacobs, have stressed the role of technological spillovers in generating growth. Because such knowledge spillovers are particularly effective in cities, where communication between people is more extensive, data on the growth of industries in different cities allow us to test some of these theories. Using a new data set on the growth of large industries in 170 U.S. cities between 1956 and 1987, we find that local competition and urban variety, but not regional specialization, encourage employment growth in industries. The evidence suggests that important knowledge spillovers might occur between rather than within industries, consistent with the theories of Jacobs.