A Mean-Variance Benchmark for Intertemporal Portfolio Theory

Mean-variance portfolio theory can apply to the streams of payoffs such as dividends following an initial investment, in place of one-period returns. This description is especially useful when returns are not independent over time and investors have non-marketed income. Investors hedge their outside income streams, and then their optimal payoff is split between an indexed perpetuity - the risk-free payoff - and a long-run mean-variance efficient payoff. "Long-run" moments sum over time as well as states of nature. In equilibrium, long-run expected returns vary with long-run market betas and outside- income betas. State-variable hedges do not appear in optimal payoffs or this equilibrium.