Forward Unbiasedness in the Short End of the Interest Rate Market

Samih Antoine Azar

doi:10.5539/ibr.v11n2p70

Abstract

Forward rate unbiasedness postulates that the forward rate is an unbiased estimator or predictor of the future spot rate. This case of risk neutrality has been tested extensively especially in the foreign exchange market. This paper departs from this line of research and studies unbiasedness at the short end of the interest rate market. Although, a priori, an investment of 6 months and an investment of three months rolled over for an additional 3 months are commonly believed to be riskless at first approximation, our results show otherwise. The precision of our estimators unveil a small but statistically significant risk premium. The latter has two components, a constant risk premium and a time-variable one. The constant risk premium is estimated to be 14.4 basis points. The time-variable risk premium ranges between a maximum of 184.6 basis points, and a minimum of -123.2 basis points, and averages 5.4 basis points. The methodology in this paper is amenable and adaptable, with little adjustments, to other maturities. This is an agenda for the future.

Highlights

The expectations theory of the term structure of interest rates is known at least since the 1930s (Fisher, 1930; Keynes 1930)
This paper studies the relation of unbiasedness between the 3-month forward interest rate, derived from US T-bills, and the 6-month US T-bill interest rate
Forward market efficiency, and unbiasedness are rejected in our sample

Summary

Introduction

The expectations theory of the term structure of interest rates is known at least since the 1930s (Fisher, 1930; Keynes 1930). In its “pure” form it states that the long interest rate is an average of expected sho rt term interest rates. This implies that the forward rate is an unbiased predictor of the future rate. If rs is a random walk the above collapses to: rlk − rs0 = ε where ε is a stationary white noise process having a mean zero, if the pure expectations theory holds, having a mean of θ if there is a stationary and constant risk or liquidity premium, and having a mean of θk if the premium depends on the maturity k.

Theory

Empirical Analysis

Findings

Conclusion