This paper aims to develop and compare bounds on the pricing formulas for European type discrete Asian options. The lower bound is found by conditioning the maturity payment of the Asian option by the geometric average and the bound derived can be expressed as a portfolio of delayed payment European call options. Several exercise price-dependent upper bounds are derived. Like the lower bound, one of the upper bounds is expressed as a portfolio of delayed payment European call options. Through a numerical analysis, we conclude that more information is gained from the readily calculated bounds than from the usually applied pricing approximations. From the closed-form solutions of the bounds, hedging positions are finally derived.

The authors derive a unified model that gives closed form solutions for caps and floors written on interest rates as well as puts and calls written on zero-coupon bonds. The crucial assumption is that simple interest rates over a fixed finite period that matches the contract, which the authors want to price, are log-normally distributed. Moreover, this assumption is shown to be consistent with the Heath-Jarrow-Morton model for a specific choice of volatility.

ABSTRACT We derive a unified model that gives closed form solutions for caps and floors written on interest rates as well as puts and calls written on zero‐coupon bonds. The crucial assumption is that simple interest rates over a fixed finite period that matches the contract, which we want to price, are log‐normally distributed. Moreover, this assumption is shown to be consistent with the Heath‐Jarrow‐Morton model for a specific choice of volatility.

Kristian R. Miltersen, Klaus Sandmann, Dieter Sondermann, Closed Form Solutions for Term Structure Derivatives with Log-Normal Interest Rates, The Journal of Finance, Vol. 52, No. 1 (Mar., 1997), pp. 409-430