Junior Can't Borrow: A New Perspective on the Equity Premium Puzzle

Ongoing questions on the historical mean and standard deviation of the return on equities and bonds and on the equilibrium demand for these securities are addressed in the context of a stationary, overlapping-generations economy in which consumers are subject to a borrowing constraint. The key feature captured by the OLG economy is that the bulk of the future income of the young agents is derived from their wages forthcoming in their middle age, while the bulk of the future income of the middle-aged agents is derived from their savings in equity and bonds. The young would like to borrow and invest in equity, but the borrowing constraint prevents them from doing so. The middle-aged choose to hold a diversified portfolio that includes positive holdings of bonds, and this explains the demand for bonds. Without the borrowing constraint, the young borrow and invest in equity, thereby decreasing the mean equity premium and increasing the rate of interest.

A Delegated Agent Asset-pricing model

Asset pricing theory has traditionally made predictions about risk and return, but has been silent on the actual process of investment. Today most investors delegate major investment decisions to financial professionals. This suggests that the instructions given by investors to their delegated agents and the compensation of those agents might be important determinants of capital market equilibrium. In the extreme when all investment decisions are delegated, the preferences and beliefs of individuals would be completely superseded by the objective functions of agent/managers. A provocative illustration of the difference between direct and delegated investing is provided based on active asset management relative to a benchmark index, a common objective function in practice. With the growing preponderance of delegated investing, future asset pricing theory will not only have to describe risk and return but, to be complete, must also be able to explain the observed objective functions used by professional managers