In equilibrium, each new capital asset must be priced properly relative to other assets. If an investor can also buy and sell assets in his portfolio costlessly and quickly, then the new asset will be accepted immediately and fully into the market and it will immediately behave as though it were a seasoned or previously available asset. However, it is often argued that recently issued bonds and seasoned or fully distributed bonds behave differently due to the frictions and risks associated with distributing a new security in the market. And it is also argued that recently issued bonds undergo a behavioral transformation as they become seasoned bonds. According to this argument there are significant empirical behavioral differences between recently issued bonds and seasoned bonds [4, 5, 7, 9, 13]. These differences disappear as the market gradually absorbs the new bond issue and the bond becomes “seasoned.”

Boquist, Racette, and Schlarbaum [3] and Livingston [6] show that a security systematic risk may be expressed as a function of its duration. These results have led to research examining the role of duration in explaining systematic risk, but Lanstein and Sharpe [5] indicate that Livingston's expression relies on the implicit assumption that extra-market covariances between securities are insignificant. Lanstein and Sharpe argue that such an assumption is unwarranted. They find a significant negative relationship between extra-market covariances and differences in duration between paired samples of common stock. Their paper suggests that duration may be associated with unsystematic risk and that any relation between duration and systematic risk is more complex than implied in [3] and [6].