This paper analyses the relationship between the efficient sets of investment portfolios and the investment holding period. Investors are allowed to hold risky assets as well as the riskless asset. The main result is that dominance in each period implies dominance in the multiperiod case. This finding holds with respect to first, second and third degree stochastic dominance. The riskless interest rate may vary from one period to another without changing the results of this paper.

Most research dealing with portfolio selection under uncertain inflation is carried out by assuming either one of the following two approximations: a linear or a quadratic approximation. In this paper, we analyze the general case, namely assume that the nominal return is the product of the real return and one plus the rate of inflation. We demonstrate that the general analysis leads to the following results that are not found in the two approximations: (1) even if we assume that nominal returns are independent of inflation, the nominal and real efficient sets will not necessarily coincide. Mean-Variance (M-V) analysis leads to a nominal efficient set, that is, a subset of the real M-V efficient set, whereas the opposite holds assuming investors maximize expected utility of real wealth. (2) Similar results are obtained when real returns are independent of inflation (the Fisher hypothesis). Assuming normality of nominal returns, we derive the CAPM in real terms or its zero beta counterpart.

Stochastic dominance rules (SD) have been extended to the case where investors are allowed to borrow and lend at the riskless interest rate. Stochastic dominance rules with a riskless asset (SDR) are much more effective than SD rules. However, it seems that this benefit is eliminated by an uncertain inflation, since riskless assets become risky once uncertain inflation is considered. We prove in this paper that SDR criteria are valid also in the face of uncertain (and independent) inflation. Moreover, while the mean-variance (MV) efficient set increases with uncertain inflation, the stochastic dominance efficient sets decrease.

ABSTRACT Stochastic dominance rules (SD) have been extended to the case where investors are allowed to borrow and lend at the riskless interest rate. Stochastic dominance rules with a riskless asset (SDR) are much more effective than SD rules. However, it seems that this benefit is eliminated by an uncertain inflation, since riskless assets become risky once uncertain inflation is considered. We prove in this paper that SDR criteria are valid also in the face of uncertain (and independent) inflation. Moreover, while the mean‐variance (MV) efficient set increases with uncertain inflation, the stochastic dominance efficient sets decrease.