Because transactions costs are smaller for allocating new cash flows than for reallocating existing asset holdings, financial flow variables are important determinants of investors' short-run asset demands. The demand-for-bonds equations implied by the resulting "optimal marginal adjustment" model of portfolio behavior constitute the demand side of a structural supply-demand model of the determination of the long-term interest rate. Empirical results, based on demand-for-bonds equations estimated using U.S. data for six major categories of bond market investors, support the optimal marginal adjustment model and show that the associated structural model of interest rate determination, which is restricted by the underlying demand-for-bonds equations, fits the data about as well as do previously developed unrestricted reduced-form term-structure equations.

The fact that most eldealy individuals in the United States choose to maintain a flat age-wealth profile, rather than buy individual life annuities, stands in contrast to central implications of the standard life-cycle model of consumption-saving behavior. The analysis in this paper lends support to an explanation for this phenomenon based either on the cost of annuities, importantly including the element of that cost due to adverse selection, or on the interaction of that cost and an intentional bequest motive. Expected yields offered on individual life annuities in the United States are lower by some 4-6%, or 2 1/2-4 1/2% after allowing for adverse selection, than yields on alternative long-term fixed-income investments. Simulations of an extended model of life-cycle saving and portfolio behavior, allowing explicitly for uncertain lifetimes and Social Security, show that yield differentials in this range can account for the observed behavior, even in the absence of a bequest motive, during the early years of retirement. By contrast, at older ages the combination of yield differentials in this range and a positive bequest motive is necessary to do so.

Benjamin M. Friedman, V. Vance Roley, Investors' Portfolio Behavior under Alternative Models of Long-Term Interest Rate Expectations: Unitary, Rational, or Autoregressive, Econometrica, Vol. 47, No. 6 (Nov., 1979), pp. 1475-1497

This paper uses a model of the valuation of bonds bearing call options, together with observed market yields on callable bonds, to infer information about the uncertainty associated with interest rate expectations. A dynamic programming solution of the model simultaneously determines both the bond price and the issuer's optimal refunding strategy, given the relevant data describing the bond and the market's expectations of future interest rates. Application of the valuation model in reverse, for quarterly average data for 1969-76, generates a time series representing the uncertainty which the market associated with its expectations of future interest rates during this interval, given the then-prevailing yields on new issues of utility bonds and industrial bonds callable after 5 years and 10 years, respectively. This uncertainty, parameterized as the standard deviation of a truncated normal distribution, fluctuated between 1/2 percent and 3/4 percent between 1969 and early 1974, then rose to sharply higher levels from mid-1974 through mid-1975, and has fluctuated between 3/4 percent and 1 percent since late 1975.

A feature of U.S. postwar business cycle experience that is by now widely documented is the tendency of the spread between the respective interest rates on commercial paper and Treasury bills to widen shortly before the onset of recessions. By contrast, the paper—bill spread did not anticipate the 1990–1991 recession. Empirical work presented in this paper supports two (not mutually exclusive) explanations for this departure from past experience. First, at least part of the paper—bill spread's predictive content with respect to business cycle fluctuations stems from its role as an indicator of monetary policy, but the 1990–1991 recession was unusual in postwar U.S. experience in not being immediately precipitated by tight monetary policy. Second, movements of the spread during the few years just prior to the 1990–1991 recession were strongly influenced by changes in the relative quantities of commercial paper, bank CDs, and Treasury bills that occurred for reasons unrelated to the business cycle. This latter finding in particular sheds light on the important role of imperfect substitutability of different short-term debt instruments in investors' portfolios, and highlights the burdens associated with using relative interest rate relationships as business cycle indicators.