When is Market Incompleteness Irrelevant for the Price of Aggregate Risk (and when is it not)?

In a standard incomplete markets model with a continuum of households that have constant relative risk aversion (CRRA) preferences, the absence of insurance markets for idiosyncratic labor income risk has no effect on the premium for aggregate risk if the distribution of idiosyncratic risk is independent of aggregate shocks and aggregate consumption growth is independent over time. In the equilibrium, which features trade and binding solvency constraints, as opposed to Constantinides and Duffie (1996), households only use the stock market to smooth consumption; the bond market is inoperative. Furthermore we show that the cross-sectional wealth and consumption distributions are not affected by aggregate shocks. These results hold regardless of the persistence of idiosyncratic shocks, and arise even when households face tight solvency constraints, but only a weaker irrelevance result survives when we allow for predictability in aggregate consumption growth.

When is Market Incompleteness Irrelevant for the Price of Aggregate Risk (and when is it not)?

We construct a model with a large number of agents who have constant relative risk aversion (CRRA) preferences. We show that the absence of insurance markets for idiosyncratic labor income risk has no effect on the premium for aggregate risk if the distribution of idiosyncratic risk is independent of aggregate shocks and aggregate consumption growth is independent over time. In the equilibrium, which features trade and binding solvency constraints, as opposed to Constantinides and Duffie (1996), households only use the stock market to smooth consumption; the bond market is inoperative. Furthermore we show that the cross-sectional wealth and consumption distributions are not affected by aggregate shocks. Equilibrium consumption allocations can be obtained by solving for an equilibrium in a version of the model without aggregate shocks, as in Bewley (1986), and then re-scaling the allocation by aggregate income. These results hold regardless of the persistence of idiosyncratic shocks, and arise even when households face tight solvency constraints, but only a weaker irrelevance result survives when we allow for predictability in aggregate consumption growth

Aggregate Implications of Micro Asset Market Segmentation

This paper develops a consumption-based asset pricing model to explain and quantify the aggregate implications of a frictional financial system, comprised of many financial markets partially integrated with one another. Each of our micro financial market's is inhabited by traders who are specialized in that markets type of asset. We specify exogenously the level of segmentation that ultimately determines how much idiosyncratic risk traders bear in their micro market and derive aggregate asset pricing implications. We pick segmentation parameters to match facts about systematic and idiosyncratic return volatility. We find that if the same level of segmentation prevails in every market, traders bear 30% of their idiosyncratic risk. With otherwise standard parameters, this benchmark model delivers an unconditional equity premium of 2.4% annual. We further disaggregate the model by allowing the level of segmentation to differ across markets. This version of the model delivers the same aggregate asset pricing implications but with only one-third the amount of segmentation: on average traders bear 10% of their idiosyncratic risk.Asset pricing; market segmentation; idiosyncratic risk

When is market incompleteness irrelevant for the price of aggregate risk (and when is it not)?

In a standard incomplete markets model with a continuum of households that have constant relative risk aversion (CRRA) preferences, the absence of insurance markets for idiosyncratic labor income risk has no effect on the premium for aggregate risk if the distribution of idiosyncratic risk is independent of aggregate shocks and aggregate consumption growth is independent over time. In equilibrium, households only use the stock market to smooth consumption; the bond market is inoperative. Furthermore, the cross-sectional distributions of wealth and consumption are not affected by aggregate shocks. These results hold regardless of the persistence of idiosyncratic shocks, even when households face tight solvency constraints. A weaker irrelevance result survives when we allow for predictability in aggregate consumption growth.Asset pricing Risk sharing